Multi-function energy system operable as a fuel cell, reformer, or thermal plant

ABSTRACT

An energy system including a converter disposed within a collection vessel for collecting exhaust generated by the converter for delivery, if desired, to a bottoming device, such as a gas turbine assembly. The bottoming device extracts energy from the waste heat generated by the converter yielding an improved efficiency energy system. The converter can be operated as a reformer, such as a steam reformer, and a partial oxidation or an autothermal reformer of hydrocarbon fuels, such as natural gas, kerosene, methanol, propane, gasoline, or diesel fuel and other chemicals. The chemical converter may also be operated as an electrochemical device. When the converter is operated as a fuel cell, electrical energy is generated when supplied with hydrogen or a hydrocarbon fuels. When operated as an electrolytic cell, the electrical energy is consumed for the production of chemical feed stocks or media for storage. The energy system can also include or be used as a thermal plant for producing pressurized, superheated vapor, or a hot thermal fluid or gas medium for commercial, industrial or power generation uses.

RELATED PATENT APPLICATION

[0001] The present patent application is a continuation-in-part patentapplication of U.S. Provisional Patent Application Serial No.60/244,257, filed Oct. 30, 2000, entitled CHEMICAL ENERGY POWER SYSTEM,the contents of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to the construction of energysystems, and more specifically relates to high performance energy orpower systems that employ chemical converters. The chemical convertersmay be electrochemical devices such as fuel cells or electrolyzers, orchemical devices such as reformers.

[0003] Electrochemical devices, such as fuel cells, convert chemicalenergy derived from fuel stocks directly into electrical energy. The keycomponents in an electrochemical device are a series of electrolyteunits having electrodes disposed over its surfaces, and a series ofinterconnectors disposed between the electrolyte units to provide serialelectrical connections. The electrolyte units have fuel and oxidizerelectrodes attached to opposite sides. Each electrolyte unit is an ionicconductor having low ionic resistance thereby allowing the transport ofan ionic species from one electrode-electrolyte interface to theopposite electrode-electrolyte interface under the operating conditionsof the converter. Various electrolytes can be used in such converters.For example, zirconia stabilized with such compounds as magnesia, calciaor yttria can satisfy these requirements when operating at an elevatedtemperature (typically around 1000° C.). The electrolyte materialutilizes oxygen ions to carry electrical current. The electrolyte shouldnot be conductive to electrons which can cause a short-circuit of theconverter. On the other hand, the interconnector must be a goodelectronic conductor. The interaction of the reacting gas, electrode andelectrolyte occurs at the electrode-electrolyte interface, whichrequires that the electrodes be sufficiently porous to admit thereacting gas species and to permit exit of product species. Electricityis generated through electrodes and the electrolyte by anelectrochemical reaction that is triggered when a fuel, e.g., hydrogen,is introduced over the fuel electrode and an oxidant, e.g., air, isintroduced over the oxidizer electrode. The electrochemical devices canalso have a tubular or planar configuration.

[0004] Alternatively, the electrochemical devices can be operated in anelectrolyzer mode, in which the electrochemical devices consumeelectricity and input reactants and produces fuel.

[0005] When an electrochemical device performs fuel-to-electricityconversion in a fuel cell mode, waste energy is generated and should beproperly processed to maintain the proper operating temperature of theelectrochemical device and to boost the overall efficiency of the powersystem. Conversely, when the device performs electricity-to-fuelconversion in the electrolyzer mode, the electrolyte must be providedwith heat to maintain its reaction

[0006] Furthermore, the device when used to reform fuel, requires theinterchange of thermal energy. Thus thermal management of theelectrochemical device for proper operation and efficiency is important.

[0007] Environmental and political concerns associated with traditionalcombustion-based energy systems, such as coal or oil fired electricalgeneration plants, are elevating interest in alternative energy systems,such as energy systems employing electrochemical devices. Neverthelesselectrochemical devices have not found widespread use, despitesignificant advantages over conventional energy systems. For example,compared to traditional energy systems, electrochemical devices such asfuel cells are relatively efficient and do not produce pollutants.Accordingly, electrochemical energy systems can benefit from additionaldevelopment to maximize their advantages over traditional energy systemsand increase the likelihood of their widespread use.

[0008] Conventional energy devices, such as gas turbine power systems,exist and are known. Prior gas turbine power systems include acompressor, a combustor, and a mechanical turbine, typically connectedin-line, e.g., connected along the same axis. In a conventional gasturbine, air enters the compressor and exits at a desirable elevatedpressure. This high-pressure air stream enters the combustor, where itreacts with fuel, and is heated to a selected elevated temperature. Thisheated gas stream then enters the gas turbine and expands adiabatically,thereby performing work. One drawback of gas turbines of this generaltype is that the turbine typically operates at relatively low systemefficiencies, for example, around 25%, with systems of megawattcapacity.

[0009] Thus, there exists a need in the art for high performance energysystems. In particular, an improved power system employing anelectrochemical device and a conventional energy device that employsstructure to increase operational efficiency while concomitantlyenhancing system safety would represent a major improvement in theindustry.

SUMMARY OF THE INVENTION

[0010] The present invention attains the foregoing and other objects byproviding methods and apparatus for mounting a reformer, fuel cell andthermal control stack within a collection vessel, and for monitoringoperational safety of the system. According to the invention, a chemicalconverter and a thermal control stack are coupled with a cogeneration orbottoming device, such as a gas turbine assembly, to form an energysystem.

[0011] The energy system of the invention includes a collection vessel,one or more chemical converters disposed within the collection vessel, athermal control stack in thermal communication with the chemicalconverter and disposed within the collection vessel, delivery means fordelivering reactants to the chemical converter or the thermal controlstack, and one or more sensors coupled to the collection vessel formonitoring a parameter of the system to ensure proper operation thereof.

[0012] According to one aspect, the system can include a gas sensor forsensing one or more constituents of the exhaust generated by the system.For example, the gas sensor can be an oxygen sensor for sensing theamount of oxygen within the exhaust.

[0013] According to another aspect, the sensor can be a UV or IR sensorfor sensing a thermal condition of a component of the system, such asthe thermal control stack.

[0014] According to another aspect, the system includes a mixer formixing a reforming agent, such as steam, with an input fuel prior tointroduction to a reformer.

[0015] According to another aspect, the chemical converter can be a fuelcell, reformer, or both. According to other aspects, the exhaustcollected by the collection vessel can be coupled to a bottoming device,such as a gas turbine assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The foregoing and other objects, features and advantages of theinvention will be apparent from the following description and apparentfrom the accompanying drawings, in which like reference characters referto the same parts throughout the different views. The drawingsillustrate principles of the invention and, although not to scale, showrelative dimensions.

[0017]FIG. 1 is a schematic block diagram of one embodiment of amultifunction energy system mounting a reformer, fuel cell, and thermalcontrol stack within a collection vessel and employing a plurality ofsensors for ensuring operational safety of the system during use.

[0018]FIG. 2 is a cross-sectional view of one embodiment of a reformerused in a chemical converter system according to the teachings of thepresent invention.

[0019] FIGS. 3A-3C are cross-sectional views of various embodiments ofthe catalyst and reforming plates of the reformer of FIG. 2.

[0020]FIG. 4 is an isometric view of an assembled fuel cell converterwith internal reforming according to the teachings of the presentinvention.

[0021]FIG. 5 is a more detailed isometric view of the electrolytecomponent and the interconnector component of a fuel cell converterallowing internal reforming.

[0022]FIG. 6 is a cross-sectional assembled view of the electrolyte andinterconnector components having various process bands disposedthereacross.

[0023]FIG. 7 graphically illustrates that the interconnector plates ofthe reformer of FIG. 2 that provide the heat transfer function among theendothermic reforming band, exothermic combustion band, and exothermicfuel cell band, resulting in an isothermal in-plane temperature

[0024]FIG. 8 is a cross-sectional view of an alternate embodiment of thethermal control stack of FIG. 1.

[0025]FIG. 9 is a cross-sectional view of an alternate embodiment of thethermal control stack employing a plurality of plates.

[0026]FIG. 10 is a cross-sectional end view of still another embodimentof the thermal control stack of FIG. 1.

[0027]FIG. 11 is a cross-sectional view of the thermal control stack ofFIG. 10.

[0028] FIGS. 12A-12E are schematic representations of the variousarrangements of the components of the energy system of the presentinvention.

[0029]FIG. 13 is a plan view, partially cut-away, of a collection vesselof the energy system of FIG. 1 according to the teachings of the presentinvention.

[0030]FIG. 14 is a schematic depiction of another embodiment of theenergy system of the present invention.

[0031]FIG. 15 is a schematic depiction of a mixer suitable for mixing areforming agent and the fuel prior to introduction to the reformer ofFIG. 1 according to the teachings of the present invention.

[0032]FIG. 16 is a schematic block diagram of one embodiment of anenergy system mounting a fuel processor, reformer and thermal controlstack within a collection vessel, and employing a plurality of sensorsfor ensuring operational safety of the system during use.

[0033]FIG. 17 is a schematic diagram of a portion of a thermal plantwhich may be optionally coupled with conventional devices for powergeneration, thermal applications or direct consumption of the outputthermal medium.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS

[0034]FIG. 1 shows one embodiment of an energy system 70 incorporating achemical converter system 72 mounted within a collection vessel 120 andan optional bottoming device, such as a gas turbine assembly 74,according to the present invention. Those of ordinary skill will readilyrecognize that the bottoming device is an optional component of thepresent invention and need not be employed.

[0035] The gas turbine assembly extracts mechanical energy from wasteheat from the exhaust generated by the chemical converter system 72. Thegas turbine assembly 74 includes a compressor 76, a turbine expander 78,and a generator 84, all connected together by shaft 82. The shaft 82 canconnect the compressor 76 to the turbine expander 78 in a serialin-line, aero-derivative configuration. The generator 84 is connected tothe turbine expander 78 by any suitable coupling. The gas turbineassembly 74 typically operates on a hydrocarbon fuel, such as naturalgas, methanol, kerosene, propane, gasoline, and diesel fuel, andinexpensively and cleanly generates electricity. Although the gasturbine assembly 74 illustrates the compressor 76, turbine expander 78,and the generator 84 mounted on the shaft 82 in sequential order, otherorders can also be utilized. For example, the generator 84 can bedisposed between the compressor 76 and the turbine expander 78. Further,the gas turbine assembly 74 can be arranged to include multiple shaftsto form a multi-shaft assembly for generating electricity.

[0036] As used herein, the phrases gas turbine and gas turbine assemblyare intended to encompass gas turbines of all power sizes, shapes andspeeds, including microturbines operating at least at 50,000 RPM, andgenerally between about 70,000 and about 90,000 RPM. A suitable gasturbine can be obtained from Capstone Turbine Corporation of Tarzana,Calif. or from Allied Signal of Torrance, Calif.

[0037] As used herein, the phrase bottoming device is intended toinclude any suitable structure that can be coupled to the chemicalconverter system 72 or the collection vessel 120 and is adapted forreceiving either exhaust or thermal energy therefrom. Examples of asuitable bottoming device include a gas turbine assembly, a steamturbine, other power systems and the like, or combinations thereof, oradapters suitable for the direct consumption of a conditioned thermalmedium. As illustrated herein, the bottoming device is a gas turbine,although other types of systems can also be used.

[0038] An oxidizer reactant, such as oxygen or air 85, is introduced tothe compressor 76 by way of any suitable fluid conduit, where it iscompressed and heated, and then discharged therefrom. The heated,compressed and pressurized air 86 is then introduced to a heat exchanger188, such as a recuperator, where it can be further heated by theturbine exhaust 184 exiting the turbine expander 78. Alternatively, aportion or all of the heated, pressurized air 86 can be intermingledwith the fuel 90 and subsequently delivered to the chemical convertersystem 72 for reforming. Those of ordinary skill will recognize that anysuitable number of fluid regulating devices can be employed in theillustrated system 70 to regulate one or more of the system fluids inorder to regulate the delivery of fluids thereto or to adjust orregulate an operational parameter of one or more system components, suchas the chemical converter system 72 and the gas turbine assembly 74.

[0039] As used herein, the terms heat exchanger or heat exchangingelement are intended to include any structure that is designed oradapted to exchange heat between two or more fluids. Examples ofsuitable types of heat exchangers adapted for use with the presentinvention include recuperators, whether internally mounted in the gasturbine assembly 74 or mounted external thereof, radiative heatexchangers, counterflow heat exchangers, regenerative type heatexchangers and the like.

[0040] In the illustrated energy system 70, a reforming agent, such aswater, and a fuel 90 are introduced to the chemical converter system 72.Specifically, the reforming agent 88 is initially passed through anoptional pre-processing treatment stage 92 for removing unwanted ions,such as cations or anions, therefrom, as well as for filtering the waterprior to introduction to the remainder of the system. The processedreforming agent is then transferred to a thermal energy source, such asa heat recovery steam generator (HRSG) 94, for converting the processedwater to steam. The HRSG 94 employs the turbine exhaust exiting therecuperator 188 for heating the water to generate steam. The reformingagent is then introduced to the reformer 110 of the chemical convertersystem 72. The HRSG can be externally mounted, as shown, or can bemounted within the collection vessel 120. In this arrangement, thethermal energy necessary to convert the water to steam, or to heat airto the appropriate temperature if used as the reforming agent, can beprovided by one or more components of the chemical converter system 72.

[0041] As used herein, the term reforming agent is intended to includeany agent sufficient to convert or change, directly or indirectly, afirst chemical species to another chemical species. Examples ofreforming agents suitable for use in the present invention includewater, air, carbon dioxide or a mixture thereof, which can be employedto convert the fuel in the presence of a chemical processor to reactionspecies, such as hydrogen and CO.

[0042] Likewise, a fuel reactant 90 passes through an optionalpreprocessing treatment stage 96, which can comprise a de-sulfurizationunit, a steam reformer, and/or a shift reactor, for removing unwantedelements or impurities, such as sulfur compounds, from the fuel 90. Thesulfur removal is important since the presence of unwanted sulfur insufficient quantities may “poison” the fuel cell of the chemicalconverter system 72. Specifically, it is known that sulfur present in afuel, such as hydrocarbon fuel, poisons the nickel catalyst of the fuelelectrode present in the fuel cell by destroying its catalytic activity.This sulfur-sensitivity is present in both low and high temperature fuelcells. Those of ordinary skill will readily recognize that the fuelpre-processing can be performed at other locations within the system 70,or can be performed by the fuel cell of the chemical converter system 72when passing therethrough. The processed fuel 99 a is introduced to acompressor 98 where it is compressed. The processed fuel 99 a can thenbe optionally mixed with the air reactant prior to introduction to thechemical converter system 72 in oxidation reforming regimes. In thisembodiment, the air functions as the reforming agent, and hence thewater 88 need not be employed. Furthermore, the processed fuel 99 a canbe optionally mixed with both air and water in the autothermal reformingprocess. The fuel and water or/and air can be introduced to the reformer110 of the chemical converter system 72 to reform the fuel into ahydrogen-rich fuel.

[0043] The energy system 70 can further include an optional mixer 176disposed within the collection vessel 120 and positioned to mix theprocessed fuel 99 a and the water 88 in a steam reforming regime (or air85 in oxidation reforming regime or both water and air in theautothermal reforming regime) prior to being introduced to the reformer110. According to one practice, the reforming of hydrocarbon fuel can beconducted by reacting water, oxygen, carbon dioxide or their mixturewith other suitable chemical species, such as described below andlocated within the reformer 110, to produce hydrogen and carbonmonoxide. In the steam reforming process, the fuel can be heated bybeing mixed with the reforming agent (steam). Thus, the steam can besuperheated prior to the point of mixture with the fuel in order toavoid accidentally condensing the steam when mixed with the cooler fuel.However, the mixer 176 avoids accidentally pyrolizing the fuel, whichcan result in unwanted carbon deposits, such as the type that can occurat temperatures of about 700° C. when utilizing natural gas. Theillustrated mixer 176 achieves this by employing the liquid state of thesteam (water) at the supply or mixing region prior to evaporation.

[0044] With reference to FIG. 1, the illustrated system 70 can include acollection vessel 120 for housing the chemical converter system 72. Thechemical converter system 72 includes one or more chemical converters,such as a reformer 110, a fuel cell 112, and/or a thermal control stack116. The illustrated reformer 110 is positioned within the collectionvessel 120 so as to receive the processed reforming agent 88 and theprocessed fuel 90. The illustrated reformer 110 reforms the fuel in thepresence of the reforming agent to produce a relatively pure fuel stock.Moreover, fuel cells utilize the chemical potential of selected fuelspecies, such as hydrogen or carbon monoxide molecules, to produceelectrical power in addition to oxidized molecules. Since the cost ofsupplying molecular hydrogen or carbon monoxide is relatively higherthan providing traditional fossil fuels, the reformer can be utilized toconvert the fossil fuels, such as coal, natural gas, methanol, kerosene,propane, gasoline, and diesel fuel, to a reactant gas mixture high inhydrogen and carbon monoxide. Consequently, a fuel processor, eitherdedicated or disposed internally within the fuel cell, can be optionallyemployed to reform, by the use of steam, oxygen, or carbon dioxide (inan endothermic reaction), the fossil fuels into non-complex reactantgases.

[0045]FIG. 2 is a cross-sectional view of one embodiment of the reformer110. The reformer 110 includes a number of thermally conductive plates12 and reforming plates 14 that are alternately stacked together to forma stacked reforming structure 13 that extends along axis 28. Thereformer includes a fluid conduit 16 that is in fluid communication withthe inner portions 12A, 14A of the plates 12, 14. The reformer 110 ispreferably housed within a gas-tight enclosure, housing or collectionvessel 20, which can be the collection vessel 120 or distinct from thecollection vessel 120. The illustrated reformer can be used to performsteam, oxidation or autothermal reforming. The heat necessary for thereforming process can be supplied internally by partial oxidation ofhydrocarbon fuel or supplied externally by a remote heat source, asshown by wavy lines 26, to the reformer 110 by radiation, conduction orconvection.

[0046] The reactant to be reformed by the reformer 110 is introducedthereto through the axial fluid manifold 16. The reactant preferablycomprises a mixture of a hydrocarbon fuel and a reforming agent, such asair, oxygen, water, CO₂ or a mixture thereof, that are premixed eitherprior to introduction to the manifold 16 or within the reformer. Theillustrated reformer 110 includes at least one manifold that delivers afuel/reforming agent mixture to the reformer, rather than provideseparate input manifolds for each gas constituent. The introduction of apremixed reactant to the reformer 110 provides for a relatively simpledesign.

[0047] The reactant mixture 22 is introduced to the manifold 16 by anyappropriate means, such as by fluid conduits. The mixture 22 enters theinner portions of the reformer through reactant passages 24 that areformed between the adjacent conductive plates 12 and reforming plates14. The passages can comprise any surface indentation or protrusions,which can be formed by embossing, and which constitutes a substantiallycontinuous fluid passage that extends from the manifold 16 to the outerperipheral surface 13A of the stacked reforming structure 13. Thepassages can also be formed by utilizing conductive or reforming platesthat are made of a porous material or have a power reformer catalystmaterial coated or formed thereon, thus allowing the reactant to passthrough the reformer.

[0048] Examples of these various plate arrangements and configurationsare illustrated in FIGS. 3A-3C. FIG. 3A illustrates the stackedarrangement of the reformer plates 14 and conductive plates 12. Thereformer plates preferably have formed thereon a reformer catalystmaterial 36 that intimately contacts the conductive plate 12. Theillustrated conductive plate 12 is embossed to form reactant flowchannels. The input reactant or the reactant mixture 22 is introduced tothe axial manifold 16 and enters the reactant channels, where it exitsthe stacked plate reformer at the peripheral edges thereof.

[0049] The reformer catalyst material can be composed of a solid orporous material. FIG. 3B illustrates the mixture flow through thereformer 110 when using a porous reforming material. The use of a porousreforming material relaxes the embossing requirements of the illustratedreformer.

[0050] In another embodiment, as illustrated in FIG. 3C, the reformer110 includes a plurality of stacked plates 38 or simply a columnalstructure that are formed of a composite of thermally conductivematerial and a reforming material. This composite plate 38 can beachieved by interspersing a suitably thermally conductive material inadmixture with a suitable reforming material. The resultant stackedstructure operates substantially identical to the stacked reformingstructure 13 shown in FIGS. 2, 3A and 3B and described above.

[0051] Those of ordinary skill will recognize that other embodiments ofthe reformer 10 exists, such as where the reforming plates 14 arecomposed of a porous material and have a reforming catalyst materialdisposed therein or coated thereon. The use of porous materials is oneof the advantages of the present external reformer since it relaxes thegas-tight requirements of the reforming system without sacrificingefficiency. Those of ordinary skill will also recognize thatconventional type reactant bed reformers or non-plate type reformers canbe used as part of the chemical converter system 72.

[0052] The reactant mixture is reformed within the stacked reformingstructure 110 as the reactant passes through the reactant passages andover or through the reforming plates 14. The catalyst materialassociated with the reforming plates 14 promotes the reforming of thehydrocarbon fuel into simpler reaction species. The stream of reactantmixture introduced to the manifold 16 can comprise H₂O, O₂, and CO₂, inaddition to a hydrocarbon fuel. For example, methane (CH₄) can becatalytically reformed into a mixture of hydrogen, water, carbonmonoxide and carbon dioxide.

[0053] When operating the reformer as a steam reformer, it receives areactant gas mixture containing natural gas (or methane), or vaporizedkerosene, methanol, propane, gasoline, or diesel fuel, and steam. Steamreforming catalyst can be formed on the reformer plate in acircumferential band. Thermal energy for the reforming reaction ispreferably conducted radially inward from the gas-tight enclosure by theconductive plates 12. The thickness and thermal conductivity of theconductive plates are selected to provide sufficient heat flow radially(or in-plane) to provide heat for the endothermic reforming reaction.The conductive plate can include an integral extension which protrudesinto the axial reactant manifold 16 for preheating the incomingreactants, as described in further detail below.

[0054] When operating the reformer as a partial oxidation reformer or anautothermal reformer, it receives a reactant gas mixture containingnatural gas (or methane), or vaporized kerosene, methanol, propane,gasoline, and diesel fuel, and air, oxygen or/and steam. One or moretypes of reforming catalyst material can be distributed incircumferential bands on the reformer plate.

[0055] The illustrated reformer 110 can be used to reform reactants suchas alkanes (paraffin hydrocarbons), hydrocarbons bonded with alcohols(hydroxyls), hydrocarbons bonded with carboxyls, hydrocarbons bondedwith carbonyls, hydrocarbons bonded with alkenes (olefins hydrocarbons),hydrocarbons bonded with ethers, hydrocarbons bonded withesterhydrocarbons bonded with amines, hydrocarbons bonded with aromaticderivatives, and hydrocarbons bonded other organo-derivatives.

[0056] The reforming plate 14 can be composed of any suitable reformingcatalytic material that operates at temperatures in the range betweenabout 200° C. and about 800° C. Examples of the types of material thatcan be used include platinum, palladium, chromium, chromium oxide,nickel, nickel oxide, nickel containing compounds, and other suitabletransition metals and their oxides. The reforming plate 14 can furtherinclude a ceramic support plate that has a reforming material coatedthereon, as illustrated in FIGS. 3A and 3B. Thus, the reforming plate 14of the present invention can include any multi-stacked reforming platestructure that includes suitable reforming catalysts that promote thereformation of a hydrocarbon fuel into suitable reaction species.

[0057] The conductive plate 12 can be formed of any suitable thermallyconductive material, including metals such as aluminum, copper, iron,steel alloys, nickel, nickel alloys, chromium, chromium alloys,platinum, and nonmetals such as silicon carbide, and other compositematerials. The thickness of the conductive plate 12 can be selected tomaintain a minimum temperature gradient in-plane of the plate 12 and tothereby provide an isothermal region for optimum reforming reaction andto alleviate thermal stress in the reforming plates 14. The conductiveplate 12 preferably forms a near isothermal condition in-plane of eachplate 12. The isothermal surface formed by the conductive plate 12improves the efficiency of the overall reforming process by providing asubstantially uniform temperature and supply of heat over the surface ofthe plate for reforming.

[0058] Furthermore, the conductive plates form an isothermal conditionalong the axis of the stack (along the outer peripheral surface of thestacked reformer 13) by the uniform distribution of the reactant mixturethrough the reactant passages, thereby preventing cold or hot spots fromdeveloping along the stack. This improves the thermal characteristics ofthe reformer 10 and improves the overall performance of the system. Asused herein, the term “isothermal” condition or region is intended toinclude a substantially constant temperature that varies only slightlyin an axial or in-plane direction. A temperature variation of at leastabout 50° C. is contemplated by the teachings of the present invention.

[0059] The reformed fuel or reaction species is exhausted along theperipheral portion 13A of the stacked reforming structure 13, asindicated by the arrows 30. The peripheral exhausting of the reactionspecies, e.g., reformed fuel products allows relatively easy manifoldingof the reactants. The exhausted fluid media are then collected by thegas-tight housing 20 and exhausted therefrom through exit conduits 32.The gas-tight housing 20 thus serves as a peripheral manifold.

[0060] In an alternate embodiment, the reactant mixture 22 can beintroduced into the peripheral manifold formed by the housing 20 andthen into the stacked reforming structure 13 along the peripheral edge.The reactant flows radially inward across the reforming and conductiveplates 14, 12 and is discharged through the axial manifold 16.

[0061] The ability to vent the reformed reactant mixture at least at asubstantial portion of the periphery of the stack, and preferably fromnearly the entire periphery, provides for an exposed peripheral surfacedevoid of a gas-tight seal or insulating material. Hence, the reformer110 of the present invention achieves a compact, simple, elegantreforming design.

[0062] The gas-tight enclosure 20 is preferably composed of a thermallyconductive material, such as metal. In the illustrated embodiment, thegas-tight enclosure 20 radiantly receives heat energy from an externalheat source and further radiantly transfers this heat energy to thestack 13 and thus to the conductive plates 12. The plates 12 supply theheat energy necessary for the reforming reaction by conductivelytransferring the heat from the outer peripheral surface 13A of the stack13 inwardly towards the reactant manifold 16. Those of ordinary skillwill recognize that the enclosure 20 can be separate from and disposedwithin the vessel 120 of FIG. 1.

[0063] In another embodiment, the outer surface of the reformingstructure 10 contacts the inner surface of the gas-tight housing, whichserves to conductively transfer the heat energy to the conductiveplates.

[0064] The gas-tight enclosure of cylindrical configuration isparticularly suitable for pressurized reformer operation. The pressurewithin the vessel is preferably between about ambient and about 50 atm,although other pressure regimes are contemplated by the presentinvention.

[0065] The technique for achieving axial reactant flow distributionuniformity is as follows. The reactant flow passages 24 are designed toensure that the total reactant flow pressure drop in the reactantpassages is significantly greater than or dominates the reactant flowpressure drop in the reactant manifold 16. More specifically, the flowresistance of the passages 24 is substantially greater than the flowresistance of the axial manifold 16. According to a preferred practice,the reactant flow pressure within the passages 24 is about ten timesgreater than the reactant flow pressure within the manifold. Thispressure differential ensures an axial and azimuthal uniformdistribution of reactant along the reactant manifold 16 and the reactantpassages 24 and essentially from top to bottom of the reformer stack 13.The uniform flow distribution ensures a uniform temperature conditionalong the axis of the reforming structure 10.

[0066] According to a preferred embodiment, the stacked reformingstructure 13 is a columnal structure, and the plates have a diameterbetween about 1 inch and about 20 inches, and has a thickness betweenabout 0.002 inch and about 0.2 inch. The term columnal as used herein isintended to describe various geometric structures that are stacked alonga longitudinal axis and have at least one internal reactant manifoldwhich serves as a conduit for a reactant mixture.

[0067] Those of ordinary skill will appreciate that other geometricconfigurations can be used, such as rectangular or rectilinear shapeswith internal or external manifolds. The plates having a rectangularconfiguration can be stacked and integrated with attached externalmanifolds for the supply and the collection of the reactant andreforming resultant species.

[0068] The relatively small dimensions of the plates 12, 14 of thereformer 10 provide for a compact plate-type reformer that reforms ahydrocarbon fuel into suitable reaction species, and which is easilyintegratable with existing power systems and assemblies. The illustratedreformer 10 can be thermally integrated with an electrochemical deviceor chemical converter, such as a solid oxide fuel cell. In the specialapplication where the reformed fuel is introduced into the fuel cell,the required heat of reaction is supplied from the waste heat generatedby the fuel cell.

[0069]FIG. 4 shows an isometric view of a reformer incorporated internalto an electrochemical converter system according to a preferredembodiment of the invention. The internal reforming electrochemicalconverter 40 is shown consisting of alternating layers of an electrolyteplate 50 and an interconnector plate 60. The interconnector plate istypically a good thermal and electrical conductor. Holes or manifoldsformed in the structure provide conduits for the fuel and oxidizergases, e.g., input reactants. Reactant flow passageways formed in theinterconnector plates, FIG. 5, facilitate the distribution andcollection of these gases.

[0070] The plates 50, 60 of the internal reforming electrochemicalconverter 40 are held in compression by a spring loaded tie-rod assembly42. The tie-rod assembly 42 includes a tie-rod member 44 seated within acentral oxidizer manifold 47, as shown in FIG. 5, that includes anassembly nut 44A. A pair of endplates 46 mounted at either end of theinternal reforming electrochemical converter 40 provides uniformclamping action on stack of alternating interconnector and electrolyteplates 50, 60 and maintains the electrical contact between the platesand provides gas sealing at appropriate places within the assembly. Theconverter 40 can be the same as the converter 112 of FIG. 1.

[0071]FIGS. 4 through 6 illustrate the basic cell unit of theelectrochemical converter 40, which includes the electrolyte plate 50and the interconnector plate 60. In one embodiment, the electrolyteplate 50 can be made of a ceramic material, such as a stabilizedzirconia material ZrO₂(Y₂O₃), an oxygen ion conductor, and a porousoxidizer electrode material 50A and a porous fuel electrode material 50Bwhich are disposed thereon. Exemplary materials for the oxidizerelectrode material are perovskite materials, such as LaMnO₃(Sr).Exemplary materials for the fuel electrode material are cermets such asZrO₂/Ni and ZrO₂/NiO.

[0072] The interconnector plate 60 preferably is made of an electricallyand thermally conductive interconnect material. The materials suitablefor interconnector fabrication include metals such as aluminum, copper,iron, steel alloys, nickel, nickel alloys, chromium, chromium alloys,platinum, platinum alloys, and nonmetals such as silicon carbide,La(Mn)CrO₃, and other electrically conductive materials. Theinterconnector plate 60 serves as the electric connector betweenadjacent electrolyte plates and as a partition between the fuel andoxidizer reactants. Additionally, the interconnector plate 60conductively transfers heat in-plane (e.g., across the surface) of theplate to form an isothermal surface, as described in further detailbelow. As best shown in FIG. 4, the interconnector plate 60 has acentral aperture 62 and a set of intermediate, concentric radiallyoutwardly spaced apertures 64. A third outer set of apertures 66 aredisposed along the outer cylindrical portion or periphery of the plate60.

[0073] The interconnector plate 60 can have a textured surface. Thetextured surface 60A preferably has formed thereon a series of dimples,which are formed by known embossing techniques and which form a seriesof connecting reactant flow passageways. Preferably, both sides of theinterconnector plate have the dimpled surface formed thereon. Althoughthe intermediate and outer set of apertures 64 and 66, respectively, areshown with a selected number of apertures, those of ordinary skill willrecognize that any number of apertures or distribution patterns can beemployed, depending upon the system and reactant flow and manifoldingrequirements.

[0074] Likewise, the electrolyte plate 50 has a central aperture 52, anda set of intermediate and outer apertures 54 and 56 that are formed atlocations complementary to the apertures 62, 64 and 66, respectively, ofthe interconnector plate 60.

[0075] As shown in FIG. 5, a reactant flow adjustment element 80 can beinterposed between the electrolyte plate 50 and the interconnector plate60. The flow adjustment element 80 serves as a fluid-flow impedancebetween the plates 50, 60, which restricts the flow of the reactants inthe reactant flow passageways. Thus, the flow adjustment element 80provides for greater uniformity of flow. A preferred flow adjustmentelement is a wire mesh or screen, but any suitable design can be usedprovided it serves to restrict the flow of the reactants at a selectedand determinable rate. Alternatively, a spacer plate can be interposedbetween the plates 50 and 60, or used in combination with the reactantflow element 80.

[0076] Referring to FIG. 5, the electrolyte plates 50 and theinterconnector plates 60 are alternately stacked and aligned along theirrespective apertures. The apertures form axial (with respect to thestack) manifolds that feed the cell unit with the input reactants, andthat exhaust spent fuel. In particular, the central apertures 52, 62form input oxidizer manifold 47, the concentric apertures 54, 64 forminput fuel manifold 48, and the aligned outer apertures 56, 66 formspent fuel manifold 49.

[0077] The absence of a ridge or other raised structure at portion ofthe periphery of the interconnector plate provides for exhaust portsthat communicate with the external environment. The reactant flowpassageways connect, fluidwise, the input reactant manifolds 47 and 48with the outer periphery of the reformer 40, thus allowing the reactantsto be exhausted externally of the converter.

[0078] The internal reforming electrochemical converter is a stackedplate assembly of cylindrical configuration, and at least one of theelectrolyte plate and the conductive plate has a diameter between about1 inches and about 20 inches, and has a thickness between about 0.002inches and about 0.2 inches.

[0079] In FIG. 6, the internal reforming electrochemical converter 240of this invention has incorporated therein additional features asdescribed below. The internal reforming operation when performed in thepresence of steam receives a reactant gas mixture containing natural gas(or methane), or vaporized kerosene, methanol, propane, gasoline, ordiesel fuel, and steam. A steam reforming catalyst 290 is distributed ina circumferential band that precedes a fuel electrode material 250Bdisposed on the electrolyte plate 250. Thermal energy for the reformingreaction is conducted radially by the plate 260 to the reforming band.The thickness and thermal conductivity of the plates is designed toprovide sufficient heat flow radially between the inner reforming band290 and the outer fuel cell band (e.g., band 250B) to provide heatenergy for the endothermic reforming reaction and to pre-heat theincoming reactants.

[0080] The internal reforming of FIG. 6 can also be performed by apartial oxidation reaction or autothernal reaction. In this mode, theillustrated converter 240 receives a reactant gas mixture containinghydrocarbon fuels such as natural gas (or methane), and air, oxygenor/and steam. One or more types of catalyst are distributed incircumferential bands preceding the fuel electrode 250B on theelectrolyte plate 250. As shown in FIG. 6, the electrolyte plateincludes an inner band that contains a combustion catalyst 292, aradially outer band 290 that contains catalysts to promote reforming ofmethane by water vapor (steam reforming) and by carbon dioxide. Thermalenergy for these endothermic reforming reactions is conducted radiallyfrom the combustion band 292 to the reforming band 290. Catalysts forother reactions, e.g. shift reactions etc. may also be incorporated. Thethickness and thermal conductivity of the conductive plates is designedto provide sufficient heat flow radially between the inner combustionband 292 and the radially outer reforming band 290 to provide theendothermic reaction energy and to pre-heat the incoming reactants.Additional thermal energy can be obtained from the exothermal fuel cellreaction performed by the fuel electrode 250B illustrated as anoutermost band along the diameter of the plate.

[0081] In the illustrated electrochemical converter 240, the combustioncatalyst 292, the reforming catalyst 290 and a shift catalyst (which canbe also applied as a band radially outward of the reforming catalyst290) can also be applied on the flow adjustment element, which issituated between the electrolyte plate and the conductive plate. Thereformer may apply the catalysts which are mixed in varying proportionsradially to maximize the production of product gas.

[0082] All of the reforming features discussed above in relation to theexternal reformer and band are equally applicable to this internalreforming electrochemical converter. For example, the interconnectorplate 260 can include extended lip portions 272A and 272B, either ofwhich can be used to preheat incoming reactants.

[0083] The internal reforming electrochemical converter 240 of thepresent invention can be a fuel cell, such as a solid oxide fuel cell,molten carbonate fuel cell, alkaline fuel cell, phosphoric acid fuelcell, and proton membrane fuel cell. The preferred fuel cell of thepresent invention is a solid oxide fuel cell. The internal reformingelectrochemical converter 240 of the present invention preferable has anoperating temperature above 600° C., and preferably between about 900°C. and 1100° C., and most preferably about 1000° C.

[0084] Those of ordinary skill will appreciate that the illustratedcombustion, reforming and fuel electrode bands are merely representativeof relative locations of electrochemical operations that occur duringuse of the converter 240 as a reformer.

[0085] In another embodiment of the invention, the internal reformingelectrochemical converter 240 can have any desirable geometricconfiguration, such as a rectilinear configuration. The stackedstructure can thus include rectangular electrolyte plates 250 andrectangular interconnector plates 260 with manifolds attached externalto the plates. The catalytic and electrode materials can be applied instrips on the electrolyte plates perpendicular to the reactants flowdirection. As illustrated in FIG. 6, the fuel flow 224 is perpendicularto the elongated bands 292, 290 and 250B. The interconnector plates 260conductively transfer heat energy to the endothermic reforming catalystband 290, the exothermic combustion catalyst band 292, and theexothermic fuel cell band 250B, resulting in a substantially in-planeisothermal condition, as illustrated in FIG. 7.

[0086]FIG. 7 graphically depicts the isothermal temperature condition ofthe incoming reactants, e.g., hydrocarbon fuel, and reformed fuelestablished by the thermally conductive plate 260 during its passagesover the electrolyte plate 250 of FIG. 6. The temperature of the fuelduring operation is defined by the ordinate axis and the fuel flowdirection is defined by the abscissa. In a reforming structure that doesnot utilize a thermally conductive plate to transfer heat in-planeduring operation, the fuel temperature varies greatly in the directionof fuel flow, as denoted by waveform 210. As illustrated, the incomingfuel is initially preheated, as by the extended surfaces 272A and 272Bof FIG. 6. This preheating stage 212 corresponds to a rise in the fueltemperature as it approaches the operating temperature of the converter240. During the exothermic partial oxidation or combustion stage 214,the temperature of the fuel further increases until the fuel flowreaches the reformation stage 216. The endothermic reformation stagerequires a significant amount of heat energy to sustain the reformingoperation. The fuel then flows to the fuel cell reaction stage 218,where the fuel is again heated, e.g., by the relatively hot operatingenvironment of the converter 240. This sinusoidal like temperatureprofile 210 of the fuel decreases the overall operating efficiency ofthe converter, as well as exposes certain components (the electrolyteplate 250) to undesirable thermal stresses. The introduction of theconductive (interconnector) plate within the converter 240 “smoothes”the temperature profile and creates a substantially isothermaltemperature condition, in-plane and axially along the converter stack,through all stages of operation as illustrated by the isothermal profile220.

[0087] According to one mode of operation, the internal reformingelectrochemical converter catalytically reforms the hydrocarbon fuelwith H₂O to produce H₂ and CO, which in turn proceeds to the fuel cellportion (e.g., fuel electrode 250B) for electricity generation. Itproduces exhaust species H₂O and CO₂. The heat from the exothermic fuelcell reaction is conductively transferred in-plane to the conductingplates to support the endothermic reforming reaction.

[0088] According to another mode of operation, the internal reformingelectrochemical converter catalytically oxidizes hydrocarbon fuel toproduce H₂ and CO, which proceeds to the fuel cell section forelectricity generation. It produces exhaust species H₂O and CO₂. Theheat from the exothermic fuel cell reaction is conductively transferredin-plane to the conductive plates 260 to support the mildly exothermicpartial oxidation reforming or autothermal reforming reaction. Theinternal reforming electrochemical converter can be placed in anenclosure designed for pressurized operation, such as the collectionvessel 120.

[0089] The illustrated electrochemical converter 40 of FIG. 4 (or 240 ofFIG. 6) is also capable of performing chemical transformation andproduction, while concomitantly producing electricity in a coproductionoperation.

[0090] According to this embodiment, the electrochemical converter 40 or240 is adapted to receive electricity from a power source, whichinitiates an electrochemical reaction within the converter and reducesselected pollutants contained within the incoming reactant into benignspecies. Hence, for example, the electrochemical converter 40 or 240 canbe coupled to an exhaust source that contains selected pollutants,including NOx and hydrocarbon species. The converter 40 or 240catalytically reduces the pollutants into benign species, including N₂,O₂ and CO₂.

[0091] With reference to FIGS. 1 and 8-11, the thermal control stack 116of FIG. 1 can be operated to heat and/or cool the fuel cell 112 duringuse. The term thermal control stack as used herein is intended toinclude any suitable structure capable of functioning either or both asa heat source or a heat sink for the chemical converter system 72. Thethermal control stack 116 can also preferably function as an isothermalsurface to decrease or eliminate temperature non-uniformities along theaxial length of the fuel cell 112. This preserves or enhances thestructural integrity of the chemical converter system 72 of the presentinvention. During use, the thermal control stack is disposed within thepressure vessel 120 and is in thermal communication with the fuel cell.The thermal control stack 116 can be mounted relative to the fuel cell112 and the reformer 110 in any selected arrangement to achieve theappropriate system thermal management. One particular arrangementsuitable for this purpose is to interdigitate the reformer, fuel cell,and thermal control stack to form a single collection of units thatachieves the desired thermal management. This arrangement can form arectangular or hexagonal pattern, or any other suitable two-dimensionalor three-dimensional arrangement. For example, as illustrated in FIGS.12A-12E, the components of the chemical converter system 72, such as thereformer 110, the fuel cell 112, and the thermal control stack 116, canhave a quadrilateral arrangement, such as a square or rectangularinterdigitated arrangement as shown in FIGS. 12A and 12B. Alternatively,the components of the chemical converter system 72 can be arranged in ahexagonal shape, as shown in FIGS. 12C-12E.

[0092] With reference again to FIG. 1, the fuel cell 112 generatesexhaust 115 that is captured or collected by the collection vessel 120.Further disposed within the collection vessel 120 is a thermal controlstack 116 that is thermally coupled to the fuel cell 112. Theillustrated thermal control stack 116 can include any selected structurefor interfacing with the fuel cell 112 in order to control, adjust orregulate the temperature of a component of the electrochemical convertersystem 72, such as the fuel cell, either alone or in combination withother temperature regulating structure. Those of ordinary skill willreadily recognize that the thermal control stack 116 can operate both asa heating device upon system start-up, and as a cooling device or heatsink during established system use. The fuel cell 112 and/or thecollection vessel 120 can employ power leads that couple the directcurrent electricity generated by the electrochemical converter system 72with the inverter 114. The inverter 114 may convert the direct currentelectricity generated by the electrochemical converter system 72 intoalternating current for subsequent transfer to a power grid, powerstorage device, or power consuming apparatus.

[0093] The thermal control stack 116 is in thermal communication withthe fuel cell 112 and is also arranged to receive both fuel 99 b andair. The thermal control stack can function as a heating element orsource by combusting fuel in the presence of air to generate heat forpreheating the fuel cell 112. This operation continues to maintain anappropriate operating temperature, typically 1,000° C., whereby the fuelcell 112 continues to consume fuel and air in order to electrochemicallyreact these reactants to produce electricity. Once the fuel cell reachesits desired operating temperature, the fuel supplied to the thermalcontrol stack can be decreased or stopped, and air can continue to passtherethrough in order to assist in removing heat from the fuel cell 112.In this arrangement, the thermal control stack functions as a coolingelement or heat sink for removing waste heat from the fuel cell duringoperation.

[0094] According to one embodiment, as shown in FIG. 8, the thermalcontrol stack 116 can be formed as an isothermal structure (heatexchanger) 227 having a porous structure 228, which receives radiatedheat from its environment (e.g., from a nearby fuel cell). A workingfluid 244, such as the oxidizer reactant, flows in an inner passagewayor reservoir 242 and permeates radially outward from an inner surface228A to the outer face 228B. The working fluid 244 can be collected byany suitable structure, such as by the collection vessel 120 of FIG. 1,and can be conveyed to other parts of the energy system 70 of FIG. 1. Toensure the axial and azimuthal uniformity of the working fluid 244 flowrate, the radial pressure drop as the working fluid permeates throughthe structure 228 is maintained to be substantially greater than thepressure of the working fluid 244 as it flows through the reservoir 242.An inner flow distribution tube may be mounted within the structure 228to enhance the flow uniformity. The working fluid 244 can also bedischarged from either axial end.

[0095] According to another embodiment, the thermal control stack 116according to the present invention can also employ a plurality ofthermally conductive plates, as depicted in FIG. 9. The thermal controlstack 116 can be formed as a stack 229 having a series of plates 246that are stacked on top of each other, as shown. The plates 246 can beformed of any suitable thermally conductive material, such as nickel andother materials typically used with fuel cells. A central fluidpassageway or reservoir 242 connects the plates, while spaces areprovided between the plates to allow a working fluid 244 to flow from aninner surface 262A to an outer surface 262B. The working fluid 244 flowsthrough the reservoir 242 connecting the plates 262. The plates 262 canhave a substantially cylindrical configuration as shown, or can have anyother suitable geometric shape, such as a tubular shape. The embodimentof FIG. 9 is particularly useful in the construction of isothermal fuelcells. For example, by using spacing elements between cell units, auniform flow of reactants can be achieved.

[0096]FIG. 10 shows a cross-sectional end view of another embodiment ofthe thermal control stack 116 suitable for use in the energy system ofFIG. 1. The illustrated stack 225 includes three concentric tubularstructures that are preferably axially spaced as shown. The inner lumen264 has a plurality of passageways 266 that extend between an inner face268A and an outer face 268B of a sleeve or tube 268. A porous sleevestructure 228 surrounds inner tube 268 and has an inner surface 228A andan outer surface 228B. The inner surface 228A is in intimate facingcontact with the outer surface of the inner tube 268, such that thetransverse passageways 266 are in fluid communication with the poroussleeve 228. The transverse passageways 266 are evenly spaced apart,although any spacing can be used.

[0097] An outer tube 269 or wall element is disposed about the poroussleeve 228 and the inner tube 268, thereby forming a substantiallyco-axial geometry. The outer tube 269 has an internal surface 269A andan external surface 269B. The interior lumen 264 of inner tube 268 formsan elongate central passageway that serves as a reservoir for theworking fluid 244 as shown in FIG. 11. The interior space between theinternal surface of the outer tube 269A and the porous sleeve outer face228B forms an elongate second passageway 267 that is substantiallyparallel to the central passageway 264.

[0098] The inner tube 268 and the outer tube 269 are preferably made ofthe same material, such as metal or ceramics. The porous sleevestructure 228 can be ceramic and serves to diffuse the flow of theworking fluid from the inner lumen to the outer lumen.

[0099] Referring to FIG. 11, the working fluid 244 flows through theelongate central lumen or passageway 264 that serves as a reservoir andwhich extends along a longitudinal axis 241. As the working fluid 244flows through the reservoir 264, the working fluid is forced through thetransverse passageways 266. The sleeve 228 overlies the transversepassageways 266 so as to receive that portion of the working fluid 244that flows through the passageways 266. The working fluid 244 permeatesradially outward through the porous sleeve 228 into the outer lumen 267where the fluid is heated by an external heat source, e.g., a fuel cellassembly or other system which requires cooling, or is cooled by otherstructure. The working fluid 244 contained within the outer lumen 267flows along the internal surface of the outer tube 269, and absorbs heatconductively transferred thereto from the external surface 269B. Theouter tube's external surface 269B can be heated by being placed indirect contact with the fuel cell assembly 112, or by being radiantlycoupled to the fuel cell 112. The distribution of the working fluid 244along the internal surface 269A of the outer tube 269 provides for theeffective transfer of heat between the working fluid 244 and theexternal environment. By selectively spacing the transverse passageways266 along the inner tube 268, the working fluid 244 collected within thesecond passageway 267 maintains a constant temperature. The uniformdistribution of the isothermic working fluid 244 along the inner surface269A creates an isothermal condition along the external surface of theouter tube 269B. The passageway size and spacing are dependent upon theouter tube 269 and the inner tube 268 diameters.

[0100] The foregoing description describes the thermal control stack 225as operating as a heat sink. Those of ordinary skill will realize thatthe thermal control stack 225 can also operate as a heat source. Forexample, the working fluid 244 can comprise a heated fluid rather than acoolant. As the heated fluid flows through the reservoir 264, heat istransferred from the external surface of the outer tube 269B to anexternal environment.

[0101] It should also be appreciated that the principles of the presentinvention can also be applied to construct isothermal fuel cells (andother electrochemical converters) by employing similar structures whichdistribute the reactants uniformly along the length of a fuel cellstack. The temperature of the stacks as a whole can be regulated and,when desired, rendered isothermal.

[0102] Other embodiments of the thermal control stack would be obviousto the skilled artisan in light of the teachings herein, and includeemploying a hollow porous cylinder that has various shaped surfacestructures disposed therein. The surface structures can be composed ofmetal or ceramic, and the porous cylinder can be composed of anysuitable material, including a wire mesh screen.

[0103] Referring again to FIG. 1, the components of the chemicalconverter system 72 are mounted within the illustrated collection vessel120. The collection vessel 120 can be any suitable vessel that is sizedand dimensioned for housing any number of chemical converters, such asthe reformer 110 and/or the fuel cell 112, and the thermal control stack116, while concomitantly functioning as a fluid collection vessel forcollecting the exhaust of the fuel cell 112 and/or the thermal controlstack 116. The collection vessel can be a “positive pressure vessel,”which is intended to include a vessel designed to operate at pressuresup to 10 atmospheres, or a vessel designed to tolerate much higherpressures, up to 1000 psi. A lower pressure vessel is useful when thebottoming device used in conjunction with the chemical converter is, forexample, an HVAC system that incorporates a heat-actuated chiller or aboiler. A higher pressure vessel is useful, for example, with theillustrated energy system 70. The illustrated collecting vessel collectsexhaust at temperatures and pressures suitable for the a bottomingdevice, such as a gas turbine assembly, a steam turbine/generator, athermal fluid boiler, a steam boiler, a heat actuated chiller, an HVACsystem, and the like.

[0104] A preferred type of collection vessel is illustrated in FIG. 13,where a collection vessel 120, which may also function as a regenerativeor recuperative thermal enclosure, encases a series of stacked chemicalconverters 122. The collection vessel 120 includes an exhaust outletmanifold 124, electrical connectors 126 and input reactant manifolds 128and 130. According to one practice, the oxidizer reactant is introducedto the resident chemical converters 122 through the manifolds 128, andthe fuel reactant is introduced through the fuel manifolds 130.

[0105] The chemical converters 122 vent exhaust gases to the interior ofthe collection vessel 120. The pressure of the exhaust gases appropriateto the bottoming device used in conjunction with the collection vesselcan be controlled through use of a pump, compressor, or through use of ablower as shown and described in U.S. Pat. No. 5,948,221 of Hsu, thecontents of which are herein incorporated by reference, for selectivelypumping an input reactant into, and hence exhaust gases out of, thechemical converters 122.

[0106] As described above, the chemical converter can be operated at anelevated temperature and at either ambient pressure or at an elevatedpressure. The chemical converter is preferably a fuel cell system thatcan include an interdigitated heat exchanger, similar to the type shownand described in U.S. Pat. No. 4,853,100, which is herein incorporatedby reference.

[0107] The collection vessel 120 can include an outer wall 136 spacedfrom an inner wall 138, thereby creating an annulus therebetween. Theannulus can be filled with an insulative material 139 for maintainingthe outer surface of the vessel at an appropriate temperature.Alternatively, the annulus can house or form a heat exchanging elementfor exchanging heat with the collection vessel. In one embodiment of aheat exchanger, the annulus and walls 138 and 136 can form a heatexchanging jacket 140 for circulating a heat exchanging fluid therein.The heat exchanger formed by the walls exchanges heat with the pressurevessel and helps maintain the outer surface at an appropriatetemperature. Of course, the use of the annulus as a cooling jacket doesnot preclude the additional use of an insulative material, located otherthan in the annulus, for reducing heat loss from the interior of thepressure vessel or for also helping to maintain the outer surface of thepressure vessel at an appropriate temperature.

[0108] In one embodiment of the invention, the heat exchanging fluidcirculated in the pressure vessel heat exchanger, such as the coolingjacket formed by walls 136 and 138 is an input reactant, such as the airinput reactant flowing in the manifolds 128. Additional manifolding (notshown) fluidly connects the annulus to the chemical converters 122 suchthat the air input reactant is properly introduced thereto. Thepreheating of the air input reactant by the cooling jacket formed bywalls 136 and 138 serves several purposes, including preheating the airinput reactant to boost efficiency by regeneratively capturing wasteheat, and cooling the outer surface of the pressure vessel 120.

[0109] In an alternate embodiment, the insulation 139 can form the innerwall (rather than wall 138) and is constantly exposed to the exhaustgenerated by the chemical converters. In this arrangement, it isimportant to ensure that any non-combusted (e.g., combustible) fuelgases exhausted by the chemical converters 122 do not accumulate withinthe vessel chamber 134 to potentially dangerous levels. In order toensure operational safety, a purge gas 100 can be introduced to thevessel chamber 134 before, during or after operation of the chemicalconverter system 72. The purge gas 100 preferably displaces the unwantedgases within the vessel chamber 134 and within the voids formed betweenthe wall 136 and the insulation 139 of the collection vessel 120 with arelatively stable gas, such as air, nitrogen and the like.

[0110] With reference again to FIG. 1, the energy system 70 furtheremploys one or more sensors coupled to the collection vessel 120 forsensing or detecting one or more parameters of one or more components ofthe system 70. For example, the sensors can be employed to ensure properoperational safety of the system 70. The illustrated system includes oneor more optional thermal sensors 170 and chemical sensors 172 that arecoupled to the collection vessel 120 and to the controller 174. Theillustrated thermal sensor 170 can be arranged to sense or detect one ormore parameters of a chemical converter, such as the thermal controlstack 116, mounted within the collection vessel 120. The sensor 170 canbe an infrared (IR) sensor, ultraviolet (UV) sensor, or a thermocoupleor thermostat that senses or detects the thermal condition of the stackto determine if proper combustion or heating is occurring in the thermalcontrol stack 116. The sensor can operate by detecting radiation fromthe thermal control stack or from a flame around the stack. Theradiation is emitted from the stack and the information is correlated bythe controller 174. The sensor can determine if proper combustion isoccurring by sensing the presence or absence of a flame (or thermalradiation). According to one practice, the system 70 can ceaseintroduction of fuel to the thermal control stack in the absence of aflame or proper combustion in order to avoid unsafe levels ofcombustible fuel from accumulating within the collection vessel 120.This can be achieved by employing one or more fluid regulating devicespositioned at appropriate locations in the system. Hence, unsafeoperation of the system 70 can be avoided or averted.

[0111] The energy system 70 can also employ a chemical sensor 172 tosense or detect exhaust collected within the collection vessel 120. Thesensor 172 can be a gas sensor that is adapted to sense or detect thepresence or absence of one or more constituent components of theexhaust, such as oxygen. The sensor can be coupled to the controller174, which controls via any suitable device the delivery of one or morereactants (e.g., fuel and/or air) to one or more components of thechemical converter system 72. According to one practice, the sensor 172is an oxygen sensor that senses the presence or absence of oxygen in theexhaust to ensure sufficient oxygen is available within the system 72,and to ensure that no unburned fuel is accidentally released from thevessel. The sensor can be coupled to the collection vessel 120 ordisposed relative to the exhaust stream 180 to sense the presence orabsence of excess oxygen.

[0112] Moreover, sensing the fluid constituent with the sensor 172 andthen regulating the delivery of fluid to the chemical converter system72 provides for optimum operational conditions within the system 70 byefficiently and easily preventing, avoiding or eliminating the creationand/or accumulation of pollutants, such as hydrocarbons, carbonmonoxide, and oxides of nitrogen, within the collection vessel. In orderfor the system to be operated properly, the oxygen concentration in theexhaust should be above the stoichiometric condition. In order toachieve optimal operation, the oxygen level or concentration isregulated relative to the stoichiometric condition. A typical and safeefficient condition is to maintain the oxygen level in the exhaust tobetween about 2% and about 4%, which corresponds to passing about 10% toabout 20% excess air reactant through the system 72. The oxygen sensorcan be any suitable sensor, such as an electrochemical sensor, thatdetermines the partial pressure of oxygen by comparing oxygenconcentration in the exhaust with the oxygen concentration in theambient environment. This sensor type is commercially available fromBosch. Oxygen sensors are well known and characterized and need not bediscussed further herein.

[0113] The illustrated energy system 70 can further include one or moretemperature sensors 178 coupled to the collection vessel 120 to sense aselected temperature therein. The sensor 178 can be positioned so as tosense the interior temperature of the collection vessel 120, the exhaust180 within or without the collection vessel 180, or one or morecomponents of the chemical converter system 72, such as the thermalcontrol stack 116, the fuel cell 112, and/or the reformer 110. Thesensor 178 can be any suitable sensor adapted to sense temperature, suchas a thermocouple. The sensor 178 can be coupled to the controller 174in order to provide a feedback loop to enable the system 70 to controlthe flow of one or more system fluids, or control the operation ofselected system components, in order to regulate, monitor, detect,maintain or vary a temperature within the system. By doing such, theillustrated system 70 can ensure that the system functions withincertain temperature ranges in order to ensure safe and efficient systemoperation.

[0114] The controller 174 can be of any conventional design, such as anindustrial ladder logic controller, a microprocessor, a stand-alonecomputing apparatus, a computing apparatus that is coupled in a networkconfiguration, or any other suitable processing device which includessuitable hardware, software and/or storage for effectuating control ofthe energy system. The phrase “computing apparatus” as used herein canrefer to a programmable or non-programmable device that responds to aspecific set of instructions in a well-defined manner and/or can executea predetermined list of instructions. The computing apparatus caninclude one or more of a storage device, which enables the computingapparatus to store, at least temporarily, data, information, andprograms (e.g., RAM or ROM); a mass storage device for substantiallypermanently storing data, information, and programs (e.g., disk drive ortape drive); an input device through which data and instructions enterthe computing apparatus (e.g., keyboard, mouse, or stylus); an outputdevice to display or produce results of computing actions (e.g., displayscreen, printer, or infrared, serial, or digital port); and a centralprocessing unit including a processor for executing the specific set ofinstructions.

[0115] With reference again to FIG. 1, the exhaust 180 collected withinthe collection vessel 120 is discharged through any suitable fluidconnections and is eventually introduced to the gas turbine assembly 74.In addition to the power generated by the fuel cell 112, the gas turbineassembly 0.74 also produces power by serving as a bottoming device toconvert the exhaust and waste heat generated by the chemical convertersystem 72 into usable electrical power, thus increasing the overallefficiency of the energy system 70. Typically, the exhaust emitted fromthe chemical converter system 72 is in the range of about 1,000° C. Theexhaust having this temperature may need to be heated or cooled prior tointroduction to the gas turbine assembly 74. In these applications, asecondary heating or cooling structure, such as an additional combustoror structure for adding or mixing in a cooling fluid, can be interposedbetween the collection vessel 120 and the gas turbine assembly 74 inorder to provide temperature regulation to the exhaust, such that theexhaust is more compatible with the operational conditions of the gasturbine assembly. In other applications, the exhaust exiting thechemical converter system is already closely matched with the gasturbine assembly 74, and hence the exhaust does not require additionalheating or cooling. In certain applications, the exhaust temperature ofthe chemical converter system 72 may be higher than a desired level. Forexample, particularly in gas turbine assemblies employing smallerturbine units, the temperature of the input drive gas is generallywithin a range of between about 800 to 900° C. Hence, the 1,000° C.exhaust temperature exiting the chemical converter system 72 andcollected within the vessel 120 is incompatible with the inputtemperature range of the gas turbine assembly. It is hence desirable toadjust, control or regulate the temperature of the exhaust of thechemical converter system 72 to match the operational requirements ofthe gas turbine assembly 74 during operation.

[0116] The exhaust 180 generated by the chemical converter system 72 anddischarged from the collection vessel 120 forms the drive gas for thegas turbine assembly and is eventually introduced to the turbineexpander 78. The turbine expander adiabatically expands the exhaust andconverts the thermal energy of the exhaust into rotary energy. Since theturbine expander 78, generator 84, and compressor 76 can be disposed ona common shaft, the generator 80 produces AC or DC electricity, and thecompressor compresses the input air reactant as described above. Thoseof ordinary skill will readily recognize that the frequency of theelectricity produced by the generator is at least 1000 Hz, and typicallyis from about 1200 to about 1600 Hz. The alternating current electricityproduced by the generator 80 can be rectified by any suitable means,such as a rectifier, to convert the alternating current electricity todirect current electricity. This direct current electricity may becombined with the direct current electricity produced by the chemicalconverter system 72, prior to transformation by the inverter 84.Additionally in this arrangement, the chemical converter system 72functions as an external combustor of the gas turbine assembly, which inturn functions as a bottoming device for the system 70.

[0117] The turbine expander 78 then generates an exhaust, referred to asthe turbine exhaust 184, which is introduced to the heat exchanger 188.A portion of the heated air 86 from the compressor 76 can optionally beintroduced to the heat exchanger 188 where it can be further heated in arecuperative or a counterflow scheme by the turbine exhaust 184 passingthrough the exchanger.

[0118] The turbine exhaust 184 exiting the heat exchanger 188 canoptionally pass through the HRSG 94 where it also facilitates theconversion of the reforming agent (water) 88 into steam for subsequentintroduction to the reformer 110. The turbine exhaust can then exhaustedor vented to other devices or to the ambient environment.

[0119] As set forth above, the inputs to the energy system 70 are anoxygen containing gas, typically air; a fuel, which is typically naturalgas, and which is principally composed of methane; and a reforming agent88. The air and fuel hence function as reactants for the chemicalconverter system 72. The input oxidizer reactant is used for oxidizingthe fuel in the fuel cell 112, which are compressed and heated by thecompressors 76. The compressed, heated and pressurized air 86 is thenheated in the heat exchanger 188 by the turbine exhaust exiting theturbine expander 78. Although the oxygen containing gas is typicallyair, it can be other oxygen-containing fluids, such as air partiallydepleted of oxygen, or air enriched with oxygen. The air and fuelreactants are consumed by the electrochemical converter 112 or thermalcontrol stack 116, which in turn generates electricity and exhaust whichis captured by the collection vessel 120.

[0120] An advantage of the energy system of FIG. 1 is that it allowselectricity to be produced in an high efficiency system by the directintegration of a highly efficient, compact electrochemical converterwith a gas turbine assembly operating as a bottoming device or plant.The integration of the chemical converter system 72 with a gas turbineassembly 74 produces a hybrid system that has an overall powerefficiency of about or greater than 70%. This system efficiencyrepresents a significant increase over the efficiencies achieved byprior art gas turbine systems and prior art electrochemical systemsalone. The illustrated hybrid system incorporates an electrochemicalconverter such as a fuel cell 112 to provide electricity and high gradethermal energy. For example, the fuel cell operates as a low NOx source,thereby improving environmental performance relative to conventional gasturbine generating plants.

[0121] A further advantage of the invention is that the system mounts achemical converter, such as the fuel cell and/or reformer, in acollection vessel with a thermal control stack. This configurationprovides for a compact and easily arranged and integratable assemblythat can be used for a variety of purposes.

[0122] Another advantage of employing multiple sensors with the system70 is that they ensure safe operation of the system without accumulatingunwanted and potentially dangerous levels of combustibles within theexhaust collected by the vessel 120.

[0123] Other variations of the above designs exist and are deemed to bewithin the purview of one of ordinary skill. For example, a series ofgas turbine assemblies may be employed, or any number of compressors,combustors and turbines may be used. The present invention is furtherintended to encompass the integration of an electrochemical converterwith most types of gas turbines, including, single-shaft gas turbines,double-shaft gas turbines, recuperative gas turbines, intercooled gasturbines, and reheat gas turbines. The present invention henceencompasses a chemical energy system that combines a chemical converterand a conventional gas turbine. According to one preferred practice ofthe invention, the converter can replace, either fully or partially, oneor more combustors of the gas turbine power system.

[0124] With reference again to FIG. 1, upon start-up operation of thechemical converter system 72, the system 70 passes the purge gas 100through the collection vessel 120 to purge the vessel chamber 134 andthe isolated void or volume 132 in order to confine fuel entering thevessel to the components of the chemical converter system 72 and tochamber 134. This purge prevents or inhibits the accumulation ofhazardous or potentially dangerous gases, such as unburned fuel, fromaccumulating in the vessel chamber 134 or the isolated space during thestartup period.

[0125] Further upon start-up operation, the thermal control stack 116functions as a start-up heater for the chemical converter system 72. Inorder to initiate start-up operation of the energy system 70, thecompressor 76 of the gas turbine assembly 74 is actuated by a separatemotor (not shown) or the generator which functions as a motor. The air85 is compressed by the compressor 76, is eventually introduced to thethermal control stack 116, and is exhausted inside the collection vessel120. Subsequent to passing air through the thermal control stack 116, asuitable fuel is introduced to the thermal control stack 116, asillustrated in FIG. 1. The air and fuel inputs of the thermal controlstack 116 can be controlled by the controller 174 to attain a prescribedheating rate of the vessel chamber 134, such as 250° C./hr. The heatgenerated by the thermal control stack 116 serves to heat the adjacentchemical converters 110 and/or 112 to the auto ignition temperature ofthe fuel. If desired, the energy system 70 can be maintained in thisthermal stand-by mode until it is necessary to bring the chemicalconverters 110 and/or 112 up to an appropriate operating temperature.Also in this steady state condition, the purge gas can be turned off.The purge gas 100 can further enter the void formed between theinsulation 139 and the vessel wall 136, FIG. 13, by diffusion or naturalconvection.

[0126] The chemical converter system 72 can be equipped for electricalgeneration with one or more fuel cells, together with one or morereformers; or for chemical production by employing only the reformers110.

[0127] If desired, the controller 174 can continue to adjust thereactants introduced to the thermal control stack 116 in order tocontinue heating the chemical converters 110 and/or 112 up to or nearthe operational temperature thereof. Once the chemical converters 110and/or 112 attains a temperature close to the normal operationaltemperature, typically 1000° C., the fuel cell 112 and reformer 110 canbe actuated. For example, the fuel 90 exiting the compressor 98 can beintermingled or mixed with the steam generated by the HRSG 94 (for steamreforming) with the mixer 176 in order to produce a relatively simplefuel stock. The reformed fuel exiting the reformer 110 is thenintroduced with the compressed air 86 to the fuel cell 112 in order tostart-up the fuel cell and to generate the required fuel cell poweroutput. Alternatively, if oxidation reforming is preferred, the fuelentering the reformer 110 can be mixed with air, rather than water/steamto produce the relatively simple fuel stock. Once the chemical convertersystem 72 is operational, the fuel supplied to the thermal control stack116 can be terminated, since the thermal control stack is no longeroperating as a heat source. By passing only air through the stack atthis juncture, the thermal control stack can operate as a heat collectoror heat sink by removing waste heat from the fuel cell 112.

[0128] As described above, the illustrated chemical converter system 72produces high temperature exhaust gas which is introduced to the turbineexpander 78 of the gas turbine assembly 74. The turbine expander 78adiabatically expands the high temperature fuel cell exhaust and thengenerates a turbine exhaust for subsequent use by the energy system 70.The turbine converts the thermal energy of the drive gas into rotaryenergy, which in turn rotates shaft 82 to generate alternating currentelectricity by the generator 80. This electricity can be combined withthe electricity generated by the chemical converter system 72 forsubsequent commercial or residential use.

[0129] During steady state operation, the primary air supply 85sequentially passes through the compressor 76, and if desired the heatexchanger 188, into the fuel cell 112, for subsequent introduction tothe gas turbine assembly 74. The energy system 70 also passes theturbine exhaust through the heat exchanger 188 in order to recoup thethermal energy present within the turbine exhaust. The thermal energy inthe turbine exhaust preheats the reactant passing through the heatexchanger. For example, passing the air 85 through the heat exchanger188 preheats the air by reclaiming waste heat present within the turbineexhaust. Similarly, the turbine exhaust is passed through the HRSG 94 inorder to convert the water to steam prior to introduction to thereformer 110.

[0130] Those of ordinary skill will readily recognize that the chemicalconverter system 72, and in particular the fuel cell 112, can functionas the combustor replacement for the gas turbine assembly 74. However,alternate embodiments are also contemplated by the present inventionwherein the gas turbine assembly 74 can include a combustor and/or arecuperator as part of the gas turbine assembly. In system designs wherethe gas turbine assembly 74 includes its own internal combustor, adifferent start-up procedure can be employed in order to actuate theenergy system 70. For example, the gas turbine assembly 74 can beactuated by any suitable start-up motor (not shown). The compressor 76can therefore establish an air flow through the gas turbine assembly.The combustor of the gas turbine then receives fuel which reacts withthe air according to a prescribed rate of heating. The thermal controlstack is also configured to receive fuel from a fuel source, and topreheat the fuel cell 112 close to its operating temperature. Theremaining operational functions of this alternate system arrangement arethe same as for the energy system 70 described above.

[0131] In an alternate embodiment of the energy system 70 of the presentinvention, the illustrated energy system 70 can include an optionalthermal jacket 190 disposed about the collection vessel 120. The termthermal jacket as used herein is intended to include any suitablestructure that is adapted to mount about the collection vessel 120 andis adapted to exchange thermal energy therewith. The illustrated coolingjacket 190 is adapted to allow passage of a selected fluid, such as theair or water, therethrough. A compressor or blower is coupled to thethermal jacket 190 and is adapted to apply a selected pressure in orderto draw or force the reforming agent through the cooling jacket 190. Inthis arrangement, the collection vessel 120 is cooled or heated,depending upon the particular application, by the air or water passingthrough the thermal jacket 190.

[0132]FIG. 14 illustrates an alternate embodiment of the energy systemaccording to the teachings of the present invention. The illustratedenergy system 300 employs a gas turbine assembly 302 that includes acompressor 304, a turbine expander 306, and a generator 308, all mountedon a shaft 310 in a serial in-line aero-derivative configuration. Thoseof ordinary skill will readily recognize that the foregoing componentscan be arranged in various ways on the shaft 310. In the illustratedsystem 300, an input reactant, such as air 316, is introduced to thecompressor 304 where it is compressed. The compressed air 318 is passedthrough a heat exchanger 340 and introduced to the collection vessel320. Specifically, the heated compressed air is introduced to acombustor 322 along with another input reactant, such as the fuel 324.The combustor 322 can include any selected structure sufficient forallowing passage of one or more reactants or fluids, and for combustingfuel in the presence of oxygen. The thermal control stack 116 of FIGS. 1and 8 through 11 are examples of a suitable combustor.

[0133] The illustrated collection vessel 320 further encloses a reformer310 that is configured to receive, if desired, the fuel 324 afterpassing through a second heat exchanger 326. A reforming agent 328, suchas water, also passes through the heat exchanger 326, and is thenintroduced to the reformer 310 within the collection vessel 320. Theillustrated reforming agent 328 reforms the fuel 324 within the reformer310 in order to produce a relatively pure fuel stock 330 that isdischarged from the collection vessel 320. The reformed fuel then passesthrough the heat exchanger 326 in a regenerative fashion. The relativelypure fuel stock, also referred to as a reformate, can be transferred toa remote location for other uses, or can be further utilized within theillustrated energy system 300. For example, the fuel stock 330 can passthrough the heat exchanger 326 to preheat the incoming fuel 324 and thewater 328 when passing therethrough.

[0134] Similarly, the compressed air 318 exiting the combustor 322 canbe collected within the collection vessel 320 and discharged therefromto serve as the drive gas 332 for the turbine expander 306 of the gasturbine assembly 302. The flow 332 is converted into rotary energy bythe turbine expander, and then converted to electricity by the generator308. The electricity can be extracted via the electrical leads 312 and314. The exhaust 334 from the turbine expander 306 and/or the flow 332from the combustor 322 can be used to preheat the compressed air 318prior to introduction to the combustor 322.

[0135] Those of ordinary skill will readily recognize that modificationsto the systems illustrated above are contemplated by the teachings ofthe present invention. For example, the illustrated chemical convertersystem 72 of FIG. 1 can be disposed within the collection vessel 320 toform an energy assembly. The energy assembly can be incorporated intomany different systems, such as an HVAC system of the type described inU.S. Pat. No. 5,948,221 and in U.S. Pat. No. 6,054,229, the contents ofwhich are herein incorporated by reference.

[0136] One embodiment of the mixer 176 of FIG. 1 suitable for use withthe present invention is illustrated in FIG. 15. The illustrated mixer176 includes a housing having a selected number of ports formed therein.For example, in a steam reforming process, the reforming agent water 88is introduced to an inlet port 196A and exits through an outlet port196B. The water is then introduced to the HRSG 94 where it is convertedto steam, and then introduced to port 196D. The housing 194 furtherincludes a port 196C for receiving the processed fuel 99 a, oralternatively unprocessed fuel, which is mixed with the steam in themixing region 198. The mixed steam and fuel then exits the mixer throughport 196E. The water 88 circulating through the mixer is separated orisolated from the steam and fuel, and serves to form a cooling zoneadjacent the mixing zone 198 to provide a selected degree of cooling toprevent, minimize, reduce or inhibit the unwanted pyrolisis of fuel whenpassing through the mixer 176. Those of ordinary skill will recognizethat although the mixer is illustrated as being mounted within thecollection vessel, other locations can also be employed, such aslocations outside of the collection vessel, provided the mixer iscoupled so as to receive the reforming agent and a fuel reactant. Thoseof ordinary skill will also recognize that the illustrated mixer can beadapted or arranged to mix the fuel with an oxidant, such as air, in anoxidation reforming process; and to mix the fuel with oxidant and steamin an autothermal reforming process. According to this regime, selectedcooling may not be necessary.

[0137]FIG. 16 illustrates an alternate embodiment of the energy system70 of the present invention. Like reference numerals designate likeparts throughout. The illustrated energy system 70 includes a chemicalconverter system 72 mounted within a collection vessel 120. The chemicalconverter system 72 includes a fuel reforming converter 110 and afinishing reforming converter 110A. The reformer 110 reforms the fuel inthe presence of a reforming agent, such as air and/or water, to producea relatively pure fuel stock. In the illustrated embodiment, thechemical converters 110 and 110A can reform the fuel in the presence ofair according to an oxidation reforming process. Those of ordinary skillwill recognize that the water reforming agent or the mixture of air andwater can be used instead of air. The reformer produces a reformate orchemical output or stock 115 that can be removed from the collectionvessel 120. The illustrated energy system 70 also provides for selectedsensors coupled to or disposed relative to the housing for ensuringproper operational of the energy system.

[0138] In operation, the illustrated energy system 70 introduces a pairof system reactants, such as the fuel 90 and air 85, to the system. Theair 85 is compressed by a compressor 76 to form a pressurized,compressed air 86, that is optionally introduced to the heat exchanger188 where it is regeneratively or recuperatively heated by the turbineexhaust 184 exiting the turbine expander 78 and passing therethrough,prior to introduction to the thermal control stack 116 and the chemicalconverters 110 and 110A, where it functions as a reforming agent for thefuel 90 in oxidation reforming regimes.

[0139] The input fuel 90 is first passed through a first preprocessingstage 96, such as a desulphurization unit, and is then introduced to acompressor 98, where the fuel is compressed. The input fuel is thenintroduced to the chemical converters 110 and 110A where it is reformedin the presence of water and/or air, and the reformate exits at thechemical output port 115.

[0140] An input reforming agent, such as water 88, is introduced to aprocessing unit 92. The illustrated processing unit can be ade-ionization unit that removes ions from the water. The water is thenpassed through a heat recovery steam generator 94 where it is convertedto steam by the heat associated with the chemical convert system 72 orwith the turbine exhaust 184 passing therethrough. The steam can then beintroduced to the mixer 176 if desired, instead of air, where itfunctions as the reforming agent in order to facilitate reformation ofthe input fuel in steam reforming regimes. The illustrated converters110 and 110A reform the fuel and produces a relatively pure fuel stock,which can be removed from the vessel 120 for use remote from the systemat the output port 115, or for use elsewhere in the system.

[0141] Similarly, a thermal control stack 116 is disposed within thecollection vessel 120 and adapted to function as a heat source duringstart-up operation or as a heat control device during steady stateoperation, as described above. The illustrated thermal control stack 116is adapted to receive air and fuel depending upon the particular systemoperation. The thermal control stack 116 produces exhaust which iscollected within the collection vessel 120 along with the exhaustgenerated by the converter 110. The collected exhaust 180 is dischargedfrom the collection vessel 120 and is introduced to a turbine expander78, which forms part of the gas turbine assembly 74. The exhaust isconverted by the turbine expander into rotary energy, which is convertedinto electricity. The turbine exhaust 184 exiting the turbine expanderpasses through the heat exchanger 188 and the heat recovery steamgenerator 94 in order to preheat a selected system fluids.

[0142] The operational safety of the energy system 70 can be monitoredby the sensors 170, 172 and 178. The sensor 170, which can be a UV or IRsensor, can be coupled to the collection vessel or relative to thevessel to monitor, sense or detect the presence or absence of a selectedthermal condition of the thermal control stack, such as a flame, inorder to ensure that fuel is being properly consumed.

[0143] The energy system 70 can further employ a gas sensor 172, such asan oxygen sensor, to ensure that an adequate oxygen level orconcentration exists within the vessel chamber to prevent, inhibit oreliminate a hazardous or dangerous accumulation of unburned, combustiblefuel. This ensures that an adequate and proper amount of oxygen existsin the chamber. The sensor 178 senses the temperature within the vessel.

[0144] One or more elements of the energy system 70 as shown in FIGS. 1and 16 can be reconfigured to form a thermal plant. For example, whenthe fuel supply 99 a and the mixer 176 are eliminated, fuel 99 b issupplied to the thermal control stack and the fuel reforming converter110 and the finishing reforming converter 110A can function as a steamgenerator and super heater. In this case, the output 115 is aconditioned thermal medium. As used herein, the term thermal plant isintended to include any structure suitable for producing a conditionedthermal medium. Examples of suitable thermal plants include a vaporgenerator, steam boiler, thermal fluid heater (hydronics), gaseousmedium heater, and superheaters. When employing a thermal plant, theillustrated system can process and provide:

[0145] 1) pressurized, saturated or superheated vapor, such as steam,

[0146] 2) hot thermal fluid in hydronic applications, or

[0147] 3) hot gas medium, such as air.

[0148] Superheated vapor, hot thermal fluid and hot gas have manycommercial or industrial uses in addition to coupling with steamturbines or gas turbines for power generation.

[0149]FIG. 17 shows a portion of a thermal plant which can be coupledwith a variety of energy devices such as steam turbines or gas turbinesfor power generation; heat exchangers for thermal applications; oradapters for the direct consumption of the conditioned thermal medium.

[0150] Those of ordinary skill will readily recognize that the chemicalconverter system can be arranged to include any suitable number orcombination of the components described above, including the fuel cell,reformer, thermal control stack, reforming converter, and thermal plant.Likewise, the system 72 can include only one or more of thesecomponents, as contemplated by the present invention.

[0151] It will thus be seen that the invention efficiently attains theobjects set forth above, among those made apparent from the precedingdescription. Since certain changes may be made in the aboveconstructions without departing from the scope of the invention, it isintended that all matter contained in the above description or shown inthe accompanying drawings be interpreted as illustrative and not in alimiting sense.

[0152] It is also to be understood that the following claims are tocover generic and specific features of the invention described herein,and all statements of the scope of the invention which, as a matter oflanguage, might be said to fall therebetween.

Having described the invention, what is claimed as new and desired to besecured by Letters Patent is:
 1. An energy system for producing at leastone of electricity, chemical stock, and a conditioned thermal medium,comprising a collection vessel, one or more converters disposed withinthe collection vessel, a thermal control stack in thermal communicationwith the chemical converter and disposed within the collection vessel,and one or more sensors coupled to the collection vessel for monitoringa parameter of the system to ensure proper operation thereof.
 2. Theenergy system of claim 1, wherein said converter comprises anelectrochemical converter.
 3. The energy system of claim 2, wherein saidelectrochemical converter comprises one of a solid oxide fuel cell, amolten carbonate fuel cell, a phosphoric acid fuel cell, an alkalinefuel cell, and a proton exchange membrane fuel cell.
 4. The energysystem of claim 1, wherein said converter comprises a chemicalconverter.
 5. The energy system of claim 4, wherein said chemicalconverter comprises a reformer.
 6. The energy system of claim 4, whereinsaid chemical converter comprises one of a steam reformer, partialoxidation reformer, autothermal reformer, and aerothermal reformer. 7.The energy system of claim 1, wherein said converter comprises a thermalconverter.
 8. The energy system of claim 7, wherein said thermalconverter comprises one of a vapor generator, vapor superheater, thermalfluid hydronic heater, and gaseous medium heater.
 9. The energy systemof claim 1, further comprising a plurality of converters including atleast one chemical reactor, one electrochemical reactor, and one thermalconverter.
 10. The energy system of claim 1, wherein said sensorcomprises a UV sensor.
 11. The energy system of claim 1, wherein saidsensor comprises an IR sensor.
 12. The energy system of claim 1, whereinsaid sensor comprises a gas sensor.
 13. The energy system of claim 1,wherein said sensor comprises an oxygen sensor.
 14. The energy system ofclaim 1, further comprising a plurality of sensors including a gassensor and at least one of a UV sensor and an IR sensor.
 15. The energysystem of claim 1, wherein the converter is adapted to operate attemperatures up to about 1500° C. and pressures up to about 1500 psi.16. The energy system of claim 1, wherein the converter comprises areformer, said reformer including a carrier having a catalyst materialdisposed thereon for reforming a fuel.
 17. The energy system of claim 1,wherein the converter comprises a fuel cell, said fuel cell including anelectrolyte having electrode material disposed thereon forelectrochemically converting a fuel into electricity.
 18. The energysystem of claim 1, wherein said thermal control stack is adapted tooperate as a heat source or a heat sink.
 19. The energy system of claim1, wherein said sensor comprises an oxygen sensor for sensing the oxygenwithin exhaust collected within the collection vessel.
 20. The energysystem of claim 1, wherein said sensor comprises at least one of athermocouple, thermostat or IR sensor for sensing a thermal condition ofthe thermal control stack.
 21. The energy system of claim 1, whereinsaid IR sensor detects whether a flame is present in the thermal controlstack when operating as a burner.
 22. The energy system of claim 1,wherein said sensor comprises a UV sensor for sensing a thermalcondition of the thermal control stack.
 23. The energy system of claim1, wherein said UV sensor detects the thermal energy of the thermalcontrol stack.
 24. The energy system of claim 1, wherein at least one ofsaid converter and said thermal control stack generates exhaust, andwherein said collection vessel is adapted to collect the exhaust. 25.The energy system of claim 1, wherein said collection vessel furthercomprises an inlet for introducing a purge gas thereto.
 26. The energysystem of claim 1, further comprising means for purging a chamber ofsaid collection vessel of a selected fluid.
 27. The energy system ofclaim 1, wherein said collection vessel comprises an outer housingforming a chamber and insulation disposed within the chamber forming anisolation void between the housing and the insulation, said systemfurther comprising means for purging the chamber and the isolation voidof a selected fluid.
 28. The energy system of claim 1, wherein saidconverter operates both as a fuel cell and as a reformer.
 29. The energysystem of claim 1, further comprising a controller coupled to the sensorand to the delivery means for controlling delivery of said reactants tothe collection vessel based on an output signal from the sensor.
 30. Theenergy system of claim 1, further comprising delivery means fordelivering a reactant to one of the converter and the thermal controlstack, said reactant including at least one of a reforming agent, fuelreactant, and oxidizer reactant.
 31. The energy system of claim 30,wherein said reforming agent comprises at least one of water, oxygen,air and CO₂.
 32. The energy system of claim 1, further comprisingdelivery means for delivering reactants to the converter or the thermalcontrol stack.
 33. The energy system of claim 1, wherein the converterand the thermal control stack produce exhaust, further comprising meansfor delivering said exhaust to a bottoming device.
 34. The energy systemof claim 1, further comprising a gas turbine assembly fluidly coupled tosaid collection vessel.
 35. The energy system of claim 34, wherein theconverter and the thermal control stack produce exhaust and saidcollection vessel collects said exhaust, said exhaust forming the drivegas for the gas turbine assembly.
 36. The energy system of claim 1,wherein said sensor comprises a temperature sensor.
 37. The energysystem of claim 1, further comprising a mixer for mixing one or morereactants with a reforming agent prior to introduction to the converter.38. The energy system of claim 37, wherein said mixer comprises ahousing having a plurality of ports formed therein.
 39. The energysystem of claim 38, wherein said ports are adapted to mix said reactantand said reforming agent within a mixing zone within the housing to fromreforming mixture.
 40. The energy system of claim 39, wherein said mixeris adapted to mix fuel and steam within said mixing zone, said mixerincluding a port for discharging said reforming mixture.
 41. The energysystem of claim 40, wherein a pair of said plurality of ports is adaptedto receive and to discharge a fluid to form a cooling zone adjacent saidmixing zone, said fluid being separated from said reactant and saidreforming agent forming said reforming mixture.
 42. The energy system ofclaim 1, wherein said converter comprises a plate-type reformer forreforming a reactant into reaction species during operation, saidreformer including a plurality of catalyst plates having associatedtherewith one or more catalyst materials for promoting reformation and aplurality of conductive plates formed of a thermally conductingmaterial, said catalyst plates and said conductive plates beingalternately stacked to form a reforming structure, the conductive platesconductively transferring heat energy in-plane to support a reformingprocess.
 43. The energy system of claim 42, wherein said reformingprocess includes one or more reforming reactions, said reformingreactions including a catalytically assisted chemical reaction betweentwo or more reaction species, and a catalytically assisted thermaldissociation of a single species.
 44. The energy system of claim 42,wherein said reforming structure includes at least one axial manifoldfor introducing the reactant thereto and at least one manifold forallowing the reaction species to exit from the reforming structure. 45.The energy system of claim 42, wherein said reforming structure has anexposed peripheral surface for exchanging heat energy with an externalenvironment.
 46. The energy system of claim 42, wherein said reformingstructure includes at least one axial reactant manifold for introducingthe reactant thereto and peripheral exhaust means for exhausting thereaction species from a peripheral portion of the reforming structure.47. The energy system of claim 42, further comprising a thermallyconductive, gas-tight housing disposed about the stacked reformingstructure to form a peripheral axial manifold, and means for allowingthe reaction species to enter the peripheral axial manifold, wherein thereaction species is captured by the gas-tight housing.
 48. The energysystem of claim 42, further comprising a thermally conductive, gas-tighthousing having means for exchanging heat energy with the externalenvironment and said conductive plate by one of radiation, conductionand convection.
 49. The energy system of claim 42, wherein an outersurface of the reforming structure contacts an inner surface of agas-tight housing, said gas-tight housing being capable of conductivelytransferring heat energy to the conductive plates.
 50. The energy systemof claim 42, further comprising a gas-tight enclosure of cylindricalconfiguration for permitting pressurized reformer operation.
 51. Theenergy system of claim 42, wherein the conductive plate includes meansfor providing a generally isothermal condition, in plane of theconductive plate.
 52. The energy system of claim 42, wherein saidreforming structure includes at least one axial reactant manifold forintroducing the reactant thereto, and wherein the conductive platesincludes extension means integrally formed thereon and extending intothe axial reactant manifold for preheating an incoming reactant.
 53. Theenergy system of claim 42, wherein at least one of the conductive plateand the catalyst plate includes an in-plane surface having passage meansfor allowing the reactant to flow over the surface of the plate.
 54. Theenergy system of claim 42, further comprising an axial manifold formedwithin the reforming structure, passage means formed between theconductive plate and the catalyst plate, and means for generating areactant flow pressure drop through the passage means between theconductive plate and the catalyst plate that is substantially greaterthan the reactant flow pressure drop within the axial manifold.
 55. Theenergy system of claim 42, further comprising a passage formed betweenthe catalyst and conductive plates for allowing an incoming reactant topass over a surface of one of the plates, said passage maintaining asubstantially uniform pressure drop to provide for a substantiallyuniform flow of reactants along an axis of the reforming structure. 56.The energy system of claim 42, further comprising means for producing asubstantially uniform temperature condition along an axis of thereforming structure.
 57. The energy system of claim 42, wherein thecatalyst plate is formed of a porous catalyst material, the porousmaterial forming passage means for allowing an incoming reactant to passthrough at least a portion of the plate.
 58. The energy system of claim42, wherein the thermally conductive plate is formed of a porousconductive material, the porous material forming passage means forallowing an incoming reactant to pass through the plate.
 59. The energysystem of claim 42, wherein the conductive plate is composed of at leastone of a nonmetal such as silicon carbide, and a composite material. 60.The energy system of claim 42, wherein the conductive plate is composedof at least one metal such as aluminum, copper, iron, steel alloys,nickel, nickel alloys, chromium, chromium alloys, platinum, and platinumalloys.
 61. The energy system of claim 42, wherein the catalyst plate iscomposed of a ceramic support plate having the catalyst materialcoating.
 62. The energy system of claim 42, wherein the catalyst plateis composed of a metallic support plate having the catalyst materialcoating.
 63. The energy system of claim 42, wherein the catalystmaterial is selected from the group consisting of platinum, palladium,nickel, nickel oxide, iron, iron oxide, chromium, chromium oxide,cobalt, cobalt oxide, copper, copper oxide, zinc, zinc oxide,molybdenum, molybdenum oxide, and other suitable transition metals andtheir oxides.
 64. The energy system of claim 42, wherein the catalystplate is composed of at least one of platinum, nickel, nickel oxide,chromium and chromium oxide.
 65. The energy system of claim 42, whereinthe reactant includes a hydrocarbon species, and at least one of O₂, H₂Oand CO₂.
 66. The energy system of claim 42, wherein the reactantincludes at least one of an alkane (paraffin hydrocarbon), a hydrocarbonbonded with alcohol (hydroxyl), a hydrocarbon bonded with a carboxyl, ahydrocarbon bonded with a carbonyl, an alkene (olifin hydrocarbon), ahydrocarbon bonded with an ether, a hydrocarbon bonded with an ester, ahydrocarbon bonded with an amine, a hydrocarbon bonded with an aromaticderivative, and a hydrocarbon bonded with another organo-derivative. 67.The energy system of claim 42, further comprising means for coupling thereaction species exiting the reformer to an external fuel cell.
 68. Theenergy system of claim 65, wherein the hydrocarbon fuel and at least oneof H₂O and CO₂ undergo an endothermic catalytic reformation to produceH₂, CO, H₂O and CO₂, the energy requirements for the endothermicreforming being supplied by energy produced by an external fuel cell,said energy being transferred from the fuel cell by the conducting platethrough in-plane thermal conduction.
 69. The energy system of claim 65,wherein the hydrocarbon fuel and 02 undergo catalytic combustion andreformation to produce H₂, CO, H₂O and CO₂, and at least one of anexothermic combustion and an exothermic reaction of an external fuelcell supplementing the energy requirements for the endothermic reformingthrough the in-plane thermal conduction of the conducting plate.
 70. Theenergy system of claim 65 or 66, wherein the hydrocarbon fuel and O₂undergo catalytic combustion with the presence of steam and reformationto produce H₂, CO, H₂O and CO₂.
 71. The energy system of claim 65 or 66,wherein the CO and H₂O undergo catalytic shift reaction to form CO₂ andH₂.
 72. The energy system of claim 42, wherein the reforming structurehas a substantially cylindrical shape.
 73. The energy system of claim42, wherein the reforming structure is cylindrical and at least one ofthe catalyst plate and the conductive plate has a diameter between about1 inch and about 20 inches, and has a thickness between about 0.002 inchand about 0.2 inch.
 74. The energy system of claim 42, wherein thereforming structure has a substantially rectangular shape, through themanifolds attached to the sides of which the reactants are introducedand exhausted.
 75. The energy system of claim 1, wherein said convertercomprises a reformer for reforming a reactant into reaction speciesduring operation, said reformer including a porous and thermallyconductive material interspersed with one or more catalyst materials toform a reforming structure, the thermally conductive materialtransferring heat energy to support the reforming process.
 76. Theenergy system of claim 1, wherein said converter comprises a plate-typereformer for reforming a reactant into reaction species duringoperation, said reformer including a plurality of plates composed of athermally conductive material interspersed with one or more catalystmaterials for promoting the reforming process, said plates being stackedtogether to form a reforming structure, the plates conductivelytransferring heat energy in-plane of the plates to support the reformingprocess.
 77. The energy system of claim 75 or 76, wherein said reformingstructure includes at least one axial manifold for introducing thereactant thereto and at least one manifold for allowing the reactionspecies to exit from the reforming structure.
 78. The energy system ofclaim 75 or 76, wherein said reforming structure has an exposedperipheral surface for exchanging heat energy with an externalenvironment.
 79. The energy system of claim 75 or 76, wherein saidreforming structure includes at least one axial reactant manifold forintroducing the reactant thereto and peripheral exhaust means forexhausting the reaction species from a peripheral portion of thereforming structure.
 80. The energy system of claim 75 or 76, furthercomprising a thermally conductive, gas-tight housing disposed about thereforming structure to form a peripheral axial manifold, and means forallowing the reaction species to enter the peripheral axial manifold,wherein the reaction species is captured by the gas-tight housing. 81.The energy system of claim 75 or 76, further comprising a thermallyconductive, gas-tight housing having means for exchanging heat energywith the external environment and said reforming structure by one ofradiation, conduction and convection.
 82. The energy system of claim 75or 76, wherein an outer surface of the reforming structure contacts aninner surface of a gas-tight housing, said gas-tight housing beingcapable of conductively transferring heat energy to the reformingstructure.
 83. The energy system of claim 75 or 76, further comprising agas-tight enclosure of cylindrical configuration for permittingpressurized reformer operation.
 84. The energy system of claim 75 or 76,wherein the reforming structure includes means for providing a generallyisothermal condition through said reforming structure.
 85. The energysystem of claim 75 or 76, wherein said reforming structure includes atleast one axial reactant manifold for introducing a reactant thereto,and wherein the reforming structure includes extension means integrallyformed therewith and extending into the axial reactant manifold forpreheating the reactant.
 86. The energy system of claim 75 or 76,wherein said reforming structure includes passage means for allowing areactant to flow through the structure.
 87. The energy system of claim75 or 76, further comprising an axial manifold formed within thereforming structure, reactant passage means for allowing a reactant toflow in-plane of the reforming structure, and means for generating areactant flow pressure drop through the passage means that issubstantially greater than the reactant flow pressure drop within theaxial manifold.
 88. The energy system of claim 86, wherein the passagemeans maintains a substantially uniform pressure drop to provide for asubstantially uniform flow of reactants along an axis of the reformingstructure.
 89. The energy system of claim 75 or 76, further comprisingmeans for producing a substantially uniform temperature condition alongan axis of the reforming structure.
 90. The energy system of claim 75 or76, wherein the conductive material is composed of at least one of anonmetal such as silicon carbide, and a composite material.
 91. Theenergy system of claim 75 or 76, wherein the conductive material iscomposed of at least one metal such as aluminum, copper, iron, steelalloys, nickel, nickel alloys, chromium, chromium alloys, platinum,platinum alloys, and other refractory metals.
 92. The energy system ofclaim 75 or 76, wherein the catalyst material is selected from the groupconsisting of platinum, palladium, nickel, nickel oxide, iron, ironoxide, chromium, chromium oxide, cobalt, cobalt oxide, copper, copperoxide, zinc, zinc oxide, molybdenum, molybdenum oxide, other transitionmetals and their oxides.
 93. The energy system of claim 75 or 76,wherein the reactant includes a hydrocarbon species, and at least one ofO₂, H₂O and CO₂.
 94. The energy system of claim 75 or 76, furthercomprising means for coupling the reaction species exiting the reformerto an external fuel cell.
 95. The energy system of claim 75 or 76,wherein the reactant includes a hydrocarbon fuel and at least one of H₂Oand CO₂ which undergo catalytic reformation to produce H₂, CO, H₂O andCO₂, and wherein an exothermic reaction of an external fuel cellsupplements the energy requirements for the endothermic reformingreaction of the reforming structure through the thermally conductivematerial.
 96. The energy system of claim 75 or 76, wherein the reactantincludes a hydrocarbon fuel and O₂ which undergo catalytic combustionand reformation to produce H₂, CO, H₂O and CO₂, and at least one of anexothermic combustion and an exothermic reaction of an external fuelcell supplements the energy requirements for the endothermic reformingreaction of the reforming structure through the thermally conductivematerial.
 97. The energy system of claim 75 or 76, wherein the reactantincludes a hydrocarbon fuel and O₂ which undergo catalytic combustionwith the presence of H₂O and reformation to produce H₂, CO, H₂O and CO₂.98. The energy system of claim 75 or 76, wherein the reforming structurehas a substantially cylindrical shape.
 99. The energy system of claim 75or 76, wherein the reforming structure is cylindrical and has a diameterbetween about 1 inch and about 20 inches.
 100. The energy system ofclaim 75 or 76, wherein the reforming structure has a substantiallyrectangular shape, through the manifolds attached to the sides of whichthe reactants are introduced and exhausted.
 101. The energy system ofclaim 1, where said thermal control stack is adapted for oxidizing ahydrocarbon fuel to produce heat energy, said thermal control stackcomprising: a plurality of conductive plates formed of a thermallyconductive material and a plurality of catalyst plates having one ormore oxidizing catalyst materials, said catalyst plates and saidconductive plates being alternately stacked to form a burner structure;wherein the catalyst material of the catalyst plate promotes theoxidation of the hydrocarbon fuel to form a resultant species; andwherein the conductive plates are capable of transferring heat energyproduced during the oxidation process to the surrounding medium by oneof radiation, conduction and convection.
 102. The energy system of claim101, wherein the thermal control stack has an exposed peripheral surfacefor exchanging heat energy with an external environment.
 103. The energysystem of claim 101, wherein the thermal control stack includes at leastone axial reactant manifold for introducing the reactant thereto andperipheral exhaust means for exhausting the reaction species from aperipheral portion of the stack structure.
 104. The energy system ofclaim 101, further comprising a thermally conductive housing disposedabout the thermal control stack and having means for exchanging heatenergy with the external environment and said conductive plate by one ofradiation, conduction and convection.
 105. The energy system of claim101, wherein an outer surface of the thermal control stack contacts aninner surface of a thermally conductive housing disposed about thethermal control stack, said housing conductively transferring heatenergy from the conductive plates during operation.
 106. The energysystem of claim 101, wherein the conductive plate includes means forproviding a generally isothermal condition, in plane of the conductiveplate.
 107. The energy system of claim 101, wherein said thermal controlstack includes at least one axial reactant manifold for introducing thereactant thereto, and wherein the conductive plates include extensionmeans integrally formed thereon and extending into the axial reactantmanifold for preheating the hydrocarbon fuel.
 108. The energy system ofclaim 101, wherein an in-plane surface of at least one of the conductiveplate and the catalyst plate includes passage means for allowing thehydrocarbon fuel to flow over the surface of the plate.
 109. The energysystem of claim 101, further comprising an axial manifold formed withinthe thermal control stack, passage means formed in an in-plane surfaceof one of the conductive plate and the catalyst plate for allowing thefuel to flow over the surface of the plate, and means for generating areactant flow pressure drop through the passage means that issubstantially greater than the reactant flow pressure drop within theaxial manifold.
 110. The energy system of claim 108, wherein the passagemeans maintains a substantially uniform pressure drop to provide for asubstantially uniform flow of reactants along an axis of the thermalcontrol stack.
 111. The energy system of claim 101, further comprisingmeans for producing a substantially uniform temperature condition alongan outer surface of the thermal control stack.
 112. The energy system ofclaim 108, wherein the catalyst plate is formed of a porous catalystmaterial, the porous material forming the passage means and allowing thereactant to pass through the plate.
 113. The energy system of claim 108,wherein the thermally conductive plate is formed of a porous conductivematerial, the porous material forming the passage means and allowing thereactant to pass through the plate.
 114. The energy system of claim 101,wherein the conductive plate is composed of silicon carbide.
 115. Theenergy system of claim 101, wherein the conductive plate is composed ofat least one refractory metal.
 116. The energy system of claim 101,wherein the catalyst plate is composed of a ceramic support plate havingthe catalyst material coated thereon.
 117. The energy system of claim116, wherein the catalyst material is selected from the group consistingof at least one of platinum, nickel, nickel oxide, chromium and chromiumoxide.
 118. The energy system of claim 101, wherein the catalyst plateis composed of at least one of platinum, nickel, nickel oxide, chromiumand chromium oxide.
 119. The energy system of claim 101, wherein thehydrocarbon fuel is premixed with an oxidizer reactant prior tointroduction to or within the axial manifold.
 120. The energy system ofclaim 101, wherein the thermal control stack has a substantiallycylindrical shape.
 121. The energy system of claim 101, wherein thethermal control stack is cylindrical and at least one of the catalystplate and the conductive plate has a diameter between about 1 inch andabout 20 inches, and has a thickness between about 0.002 inch and about0.2 inch.
 122. The energy system of claim 1, wherein the thermal controlstack comprises a porous and thermally conductive material interspersedwith one or more catalyst materials to form a burner structure, whereinthe catalyst material promotes the oxidation of the hydrocarbon fuel toform a resultant species, and wherein the conductive material is capableof transferring heat energy produced during the oxidation process to thesurrounding medium by one of radiation, conduction and convection. 123.The energy system of claim 1, wherein the thermal control stackcomprises a plurality of plates composed of a thermally conductivematerial interspersed with one or more catalyst materials, said platesbeing stacked together to form a burner structure, wherein the catalystmaterial promotes the oxidation of the hydrocarbon fuel to form aresultant species, and wherein the conductive material transferring heatenergy produced during the oxidation process to the surrounding mediumby one of radiation, conduction and convection.
 124. The energy systemof claim 1, wherein said converter comprises a plate-typeelectrochemical converter having: a plurality of gas-tight electrolyteplates having reactive materials disposed on both sides thereof, saidplates having a fuel flow side and having the reactive material disposedthereon selected from the group consisting of at least one of acombustion catalyst, a reforming catalyst, a shift catalyst and a fuelelectrode material, said plates having an oxidant flow having thereactive material disposed thereon selected from the group consisting ofan oxidant electrode material, a plurality of gas-tight conductiveplates formed of a thermally conductive material; said electrolyteplates and said conductive plates being alternately stacked together toform a stacked plate assembly, and internal reforming means forpreheating and reforming a hydrocarbon fuel on the fuel flow side of theelectrolyte plate within the stacked plate assembly, said reformingbeing assisted by the conductive plates which are capable ofconductively transferring heat from a fuel cell reaction portion of thestacked plate assembly.
 125. The energy system of claim 124, wherein theelectrolyte plate performs an electrolytic ionic transfer function, suchas transferring oxygen ions.
 126. The energy system of claim 124,wherein the converter performs chemical transformation and productionwhile consuming oxygen to produce electricity.
 127. The energy system ofclaim 124, wherein a side of the conductive plate faces the fuel flowside having disposed thereon at least one of the combustion catalyst,the reforming catalyst and the shift catalyst.
 128. The energy system ofclaim 124, wherein at least one of the combustion catalyst, thereforming catalyst and the shift catalyst can be applied on a flowadjustment element, said flow adjustment element being situated betweenthe electrolyte plate and the conductive plate.
 129. The energy systemof claim 124, further comprising a plurality of axial manifolds formedin the stacked plate assembly, at least one of the manifolds beingadapted to receive a hydrocarbon fuel reactant and to allow the fuel toflow over one surface of the electrolyte plate and to exit at theexternal edge of the plates; and at least one other of said manifoldsbeing adapted to receive an oxidizer reactant and to allow the oxidizerflow over the other side of the electrolyte plate and to exit at theexternal edge of the plates.
 130. The energy system of claim 124,wherein the stacked plate assembly has a rectangular configuration withan edge that is adapted to receive a hydrocarbon fuel reactant, saidreactant flowing into the space over one surface of the electrolyteplates and exits from an opposing plate edge; and the third plate edgebeing adapted to receive an oxidizer reactant that flows into a spaceover the other surface of the electrolyte plate and exits from a fourthplate edge.
 131. The energy system of claim 124, wherein said conductingplates include means for regulating the in-plane temperaturedistribution of the stacked plate assembly to attain a substantiallyin-plane isothermal condition.
 132. The energy system of claim 129,wherein said manifolds providing means for regulating the uniform flowdistribution into the spaces between the plates along the axis of thestacked assembly to provide an axially isothermal condition.
 133. Theenergy system of claim 124, wherein the thermally conductive material ofthe conductive plate is composed of at least a nonmetal, includingsilicon carbide.
 134. The energy system of claim 124, wherein thethermally conductive plate is composed of at least one of nickel, nickelalloys, chromium, chromium alloys, platinum, and platinum alloys. 135.The energy system of claim 124, wherein the thermally conductive plateis composed of at least one of aluminum, copper, iron, and steel alloys.136. The energy system of claim 124, wherein the fuel electrode iscomposed of at least one of nickel, a nickel containing compound,chromium and chromium containing compound.
 137. The energy system ofclaim 124, wherein the combustion catalyst is composed of at least oneof a platinum, platinum containing compound, nickel and nickelcontaining compound.
 138. The energy system of claim 124, wherein thereforming catalyst is composed of at least one of a nickel, a nickelcontaining compound, chromium and a chromium containing compound. 139.The energy system of claim 124, wherein the reforming catalyst iscomposed of at least one of platinum, palladium, nickel, nickel oxide,iron, iron oxide, chromium, chromium oxide, cobalt, cobalt oxide,copper, copper oxide, zinc, zinc oxide, molybdenum, and molybdenumoxide.
 140. The energy system of claim 124, wherein partial oxidationoccurs over the combustion catalyst formed on the surface of at leastone of the electrolyte plate and the conductive plate.
 141. The energysystem of claim 124, wherein the internal reforming reaction occurs overthe reforming catalyst on the surface of at least one of the electrolyteplate and the conductive plate.
 142. The energy system of claim 124,wherein the fuel cell reaction occurs over the electrode material onboth the surfaces of the electrolyte plate.
 143. The energy system ofclaim 124, wherein the reforming catalyst and the fuel electrodematerial are intermixed over the surface of the electrolyte plate tosubstantially simultaneously reform the fuel and create electrochemicalreaction during operation.
 144. The energy system of claim 124, whereinthe combustion catalyst, reforming catalyst and the fuel electrodematerial are intermixed over the surface of the electrolyte plate tosubstantially simultaneously initiate partial oxidation and reformationof a fuel reactant and an electrochemical reaction.
 145. The energysystem of claim 124, wherein a hydrocarbon fuel introduced to theconverter catalytically reforms in the presence of H₂O, the fuel toproduce H₂ and CO, said reformed fuel being subjected to a fuel cellreaction to form an exhaust species containing H₂O and CO₂; wherein theheat from the exothermic fuel cell reaction is conductively transferredin-plane to the conductive plates to support the endothermic reformingreaction.
 146. The energy system of claim 124, wherein a hydrocarbonfuel introduced to the converter catalytically combusts partially withO₂ to produce H₂ and CO, said partially combusted fuel being subjectedto an exothermic fuel cell reaction to form an exhaust speciescontaining H₂O and CO₂, wherein the heat generated from the exothermicfuel cell reaction is conductively transferred in-plane to theconducting plates to provide a temperature sufficient to support themild exothermic partial oxidation reforming reaction.
 147. The energysystem of claim 124, wherein a hydrocarbon fuel introduced to theconverter catalytically combusts partially with O₂ in the presence ofH₂O to produce H₂ and CO, said partially combusted fuel being subjectedto an exothermic fuel cell reaction to form an exhaust speciescontaining H₂O and CO₂, wherein the heat generated from the exothermicfuel cell reaction is conductively transferred in-plane to theconducting plates to provide a temperature sufficient to support themild exothermic partial oxidation reforming reaction.
 148. The energysystem of claim 124, wherein the reactant includes at least one of analkane (paraffin hydrocarbon), a hydrocarbon bonded with alcohol(hydroxyl), a hydrocarbon bonded with a carboxyl, a hydrocarbon bondedwith a carbonyl, an alkene (olifin hydrocarbon), a hydrocarbon bondedwith an ether, a hydrocarbon bonded with an ester, a hydrocarbon bondedwith an amine, a hydrocarbon bonded with an aromatic derivative, and ahydrocarbon bonded with another organo-derivative.
 149. The energysystem of claim 124, wherein the converter is a fuel cell selected fromthe group consisting of solid oxide fuel cell, molten carbonate fuelcell, alkaline fuel cell, proton exchange membrane fuel cell, andphosphoric acid fuel cell.
 150. The energy system of claim 124, whereinthe electrolyte plate is composed of one of a zirconia based material,and a ceria based material, a bismuth based oxide, lanthanum gallate,molten carbonate or a composite of any of the foregoing materials. 151.The energy system of claim 124, further comprising reactant heatingmeans disposed within one of the manifolds for heating at least aportion of at least one of said reactants passing through said manifold.152. The energy system of claim 151, wherein said reactant heating meanscomprises a thermally conductive and integrally formed extended surfaceof said conductive plate that protrudes into at least one of saidmanifolds.
 153. The energy system of claim 152, wherein said fuel cellreaction generates waste heat which heats said reactants to about saidoperating temperature, said waste heat being conductively transferred tosaid reactants by said interconnect plate and said extended surface.154. The energy system of claim 124, further comprising peripheralexhaust means for exhausting the reformed fuel from a peripheral portionof the stacked plate assembly.
 155. The energy system of claim 124,wherein at least one of the conductive plate and the electrolyte plateincludes a reactant passage for allowing the reactant to pass from theaxial reactant manifold over the surface of the plates.
 156. The energysystem of claim 155, wherein the reactant passage includes means formaintaining a substantially uniform pressure drop over at least onesurface of the plates to provide for a substantially uniform flow ofreactant over the plate surfaces.
 157. The energy system of claim 155,wherein the reactive coating of the electrolyte plate is porous, theporous coating forming the reactant passage.
 158. The energy system ofclaim 124, further comprising means for generating a reactant flowpressure drop through a space formed between the conductive plate andthe opposing electrolyte plate that is substantially greater than thereactant flow pressure drop within the axial manifold.
 159. The energysystem of claim 124, further comprising means for producing asubstantially uniform radial flow distribution of reactants through saidstacked plates.
 160. The energy system of claim 124, wherein the stackedplate assembly is cylindrical and at least one of the electrolyte plateand the conductive plate has a diameter between about 1 inches and about20 inches, and has a thickness between about 0.002 inches and about 0.2inches.
 161. The energy system of claim 124, wherein said conductiveplates conduct heat in the in-plane direction from one end region of theplate to the another.
 162. The energy system of claim 124, wherein saidelectrolyte plate comprises a plurality of zones spaced along a surfaceof the plate for effecting selected reactions, said zones including acombustion zone, a reforming zone, and an electrochemical zone.
 163. Theenergy system of claim 124, wherein said conductive plate forms a nearisothermal temperature condition in-plane of said electrolyte and saidconductive plates.
 164. The energy system of claim 42 or 75, whereinsaid reforming structure extends, in one orientation, along an axis, andwherein said reforming structure includes at least one axial manifoldfor introducing the reactant thereto.
 165. The energy system of claim 42or 75, wherein said reforming structure comprises peripheral exhaustmeans for exhausting the reaction species from a peripheral portion ofthe reforming structure.
 166. The energy system of claim 1, wherein saidconverter is adapted to receive electricity from a remote power source,said electricity initiating an electrochemical reaction within saidconverter which is adapted to reduce selected pollutants containedwithin the incoming reactants into benign species.
 167. The energysystem of claim 166, wherein the catalytic converter further includesmeans to receive exhaust containing selected pollutants, including NOxand hydrocarbon species, the catalytic converter including means forreducing the NOx and the hydrocarbon species into benign species,including one of N₂, O₂ and CO₂.
 168. The energy system of claim 1,wherein the converter comprises a plate-type catalytic converter havinga plurality of gas-tight converter plates having disposed on a firsthydrocarbon gas side a reactive material consisting of one of aconverter catalyst and a first electrode material; and disposed on asecond buffer gas side a reactive material consisting of a secondelectrode material; a plurality of gas-tight conductive plates formed ofa thermally conductive material; said converter plates and saidconductive plates being alternately stacked together to form a converterassembly; means for introducing a hydrocarbon gas to the hydrocarbon gasside of the converter plate and introducing a buffer gas to the secondbuffer gas side of the converter plate; means for receiving electricityfrom a remote power source; and means for converting the hydrocarbon gasinto benign species.
 169. The energy system of claim 168, wherein theconductive plates include means for attaining a generally isothermalcondition in-plane of the conductive plates.
 170. The energy system ofclaim 168, wherein the converter plate is formed of a substantially gastight electrolyte material.
 171. The energy system of claim 168, whereinthe converter plate is a gas tight ionic conductor.
 172. The energysystem of claim 168, wherein the electrode coatings of at least one sideof the converter plate includes nickel or a nickel containing compound.173. The energy system of claim 168, wherein the electrode coatings ofat least one side of the converter plate includes platinum.
 174. Theenergy system of claim 168, wherein the electrode coating of at leastone side of the converter plate includes palladium.
 175. The energysystem of claim 168, wherein electricity received by said converterinitiates an electrochemical reaction which reduce selected pollutantswithin the hydrocarbon gas into the benign species.
 176. The energysystem of claim 168, wherein the assembly is adapted to receive exhaustcontaining selected pollutants, including at least one of NOx andhydrocarbon species, the catalytic converter further including means forreducing the NOx and hydrocarbon species into benign species.
 177. Theenergy system of claim 1, wherein said converter or said thermal controlstack comprises a stack of plates with axial manifold form therein, saidsystem further comprises a tie-rod assembly for clamping the stack ofplates together.
 178. The energy system of claim 177, wherein thetie-rod assembly comprises at least one tie-rod axially mounted withinthe said manifold or external to the stack, and a pair of support platesmounted on opposite ends of the stack.
 179. The energy system of claim178, wherein tie rod is extended to reach a low temperature region wherea spring load is applied to provide the clamping force.
 180. The energysystem of claim 178, wherein said converter comprises a fuel cell stack,and said tie-rod operates as an electrical connecting rod.
 181. Theenergy system of claim 1, wherein the said converter or said thermalcontrol stack comprises a gas-tight housing of cylindrical configurationconfigured to surround the said converter or stacks to permitpressurized operation.
 182. The energy system of claim 1, wherein theconverter and the thermal control stack are positioned interdigitally ina square or hexagon pattern.
 183. An energy system for producing atleast one of electricity and a chemical stock, comprising a collectionvessel, one or more converters disposed within the collection vessel, athermal control stack in thermal communication with the chemicalconverter and disposed within the collection vessel, and a mixer formixing one or more reactants with a reforming agent prior tointroduction to the converter.
 184. The energy system of claim 183,wherein said mixer comprises a housing having a plurality of portsformed therein.
 185. The energy system of claim 184, wherein said portsare adapted to mix said reactant and said reforming agent within amixing zone within the housing to from reforming mixture.
 186. Theenergy system of claim 185, wherein said mixer is adapted to mix fueland steam within said mixing zone, said mixer including a port fordischarging said reforming mixture.
 187. The energy system of claim 186,wherein a pair of said plurality of ports is adapted to receive and todischarge a fluid to form a cooling zone adjacent said mixing zone, saidfluid being separated from said reactant and said reforming agentforming said reforming mixture.